Hi Bradley and what a lovely mail and hello from Oz to beautiful South Carolina
Now, being a gal there are obviously a few extras that men don't have to worry about but I think that 28 litres should be more than enough. The key thing is that those few extra litres gives you room to have a few niceties to change into at the end of the day. Men can where the same spare shorts day after day after day and some how you still love us, which just goes to show that miracles do happen, ha ha. In regard to clothes for this adventure it really depends on how much you are willing to invest. I do a lot of long distance walking, which means over the years I've invested in the best technical equipment possible. Compare this to tennis. In the beginning you start with a $40 hand-me-down racket. After a few years and you're playing 3 times per week you spoil yourself with a $300 racket because it brings out your best. However, I'm not suggesting you do that now. There is a great French sports chain called Decathlon. Great everyday products at the right price. Long story short. The T shirt in my photo is of a special material with carbon fibre woven through and you can wear it of 5 days straight and smell nothing. It whisks away sweat and you don't get a chill in relative cool, humid environments. Price for a T shirt like this $120! And I take two on every walk. But let's be practical. First, DON'T use any cotton T shirts. Cotton retains sweat, quickly becomes very smelly and takes a long time to dry. Synthetics Ts, even cheap and cheerful are much better. It's not about cold weather gear but about layering up and layering down.
Ok, and I hope you don't mind me getting personal, and providing a complete solution, but we are talking about making life easier for a very long walk. And, after all we are all the same folks from top to bottom! I wear nylon swimmers or in your case a bikini bottom for two reasons. You can wash at the end of each day and they will be dry overnight and during a hot day you can have a quick dip in a river or lake and no need to change. Keep those special undies for the after shower arrival in the town where you are staying for the night. Likewise (and please keep in mind I am a grandfather) wear a sports bra. Every step, especially going down a steep hill is 4 - 6 times your body weight on each knee, ankle, foot and #^*. Gravity does it's thing and depending on your body shape, that's a lot of stress on your body. T shirt as above. Depending on the temp, and if it's still quite cold, I have a Rab Aeon Plus Zip Tee. It's a long sleeve T that zips to the top of the breast bone. This allows the addition of a scarf or muffler in very cold weather but also allows air in if you start feeling hot. Over the Rab or a short sleeve T I wear an Icebreaker 260 mid-weight sleeveless vest. It's incredibly light but extremely warm because it's 100% marino wool from our good friends in New Zealand. Over that I wear a 'The North Face' Polartec fleece. Again light but effective. You can buy a windstopper fleece but no doubt you are also caring an outer shell which stops wind and rain. Why carry two wind stoppers? If it's that cold, just wear your outer shell over your long sleeve fleece. And my outer shell is a Marmot, triple gore-tex jacket with an adjustable hood to close around the face in windy/wet conditions (whatever brand, make sure you have long zippers under the armpits to allow cooling in hot, steamy but wet conditions). Weighs nothing but you could stand under the shower fully clothed and stay dry. I use both long trousers and shorts from Craghoppers. I find zip off trousers, that convert to shorts, heavier than necessary and not as comfortable.
Ok, I know you have just asked yourself, why did I ask this guy for advice but it's all about the combinations and permutations of what you can do with very little kit.
For example, on a relatively warm but wet day, wear your wet weather pants over your swimmers/undies (ok poncho fans this is not for you but if you buy rain pants, make sure that they have zippers up to the knee because trying to get rain pants, with elastic cuffs over your boots or trainers will drive you insane or if it's a sudden rain burst leave you drenched by the time you get them on). No need to wear long pants or shorts as well under your rain pants. If the sun comes out, find a quiet spot and change into your shorts. I think I mentioned in a post to Eve that on a long distance walk you get to see a lot of other people's undies but who cares. We're all part of the fraternity called long distance walkers. You learn to look the other way. Mid warm day, wear your T shirt and your sleeveless vest. Layer up and layer down. The key is to leave heavy material like jeans at home.
I hope I haven't confused you and you certainly don't need to spend a lot of money but apply the KISS principle - keep it simple silly! And don't hesitate to ask more questions if you'd like me to provide more detail. I love this stuff and even after 20 years of trekking, you never stop learning. And, don't get me started on water systems and the best way to keep the water bladder and tube clean. But that's a story for another time.
In regard to feeling nervous, me too. It's a hell of a long way but in the end we are breaking the walk into small digestible chunks of 25 - 30 kilometres each. And, when you think about it, we walk every day. Perhaps not so far but this time we are following a set trail as opposed to around our home town or city. Plus, you will be surrounded by fellow walkers who all have the same objective. Before you know it you will have completed the first week, found your rhythm and be confident with starting each new day. For me the key thing is that this isn't a contest. Listen to your body. If you are going with a friend or partner, and he or she has longer legs and quicker, let them go ahead or vice versa. You will catch up with each other at some point in the day. And, DON'T power-walk (there's the father in me again). Can you imagine power-walking for 35 days! Just find the pace that's comfortable for your height and frame. Trust me, the next town will still be there waiting for you when you arrive, ha ha.
Happy trails