Hi Anna,
First, let us talk about the emotion, fear, or, False Evidence Appearing Real. In my youth, I also, was afraid of things, being a natural introvert. At 30 I started practicing Aikido and Ki (specific Aikido style using inner energy, same as Chi). I spent the next 34 years training and teaching. So, teaching has become natural to me as well. The key point here is that I learned to diminish the introvert Michelle and bring out a bit of me that loves to live and truly, now, has no fear.
Can this be accomplished in a matter of a few weeks? Yes.
For me, my shedding of my fears came one day where I placed myself in front of what I feared. I could back away and allow my fear to control me, or I could move forward, allow myself to live with true freedom to do what I want, when I want and where I want.
For you, right now, the Camino is an unknown. But allow me to put you there on March 29, as if it was right now, (maybe like time travel). You get off the plane, glance around seeking others with backpacks, (you may not be the only Pilgrim there). Approach them, ask in a friendly way, "Just wondering if you are a Pilgrim?" If no, that is ok, apologize and look for the next one. What you are doing is breaking the ice with strangers, while not only seeking like minded individuals but also looking for others to share a taxi to an albergue.
So, you find a couple of new friends and find out that they are looking for a place to stay as well, so out you go for a taxi. You find one and ask, "Habla in gles, Senor?" Hoping he does to make it easy. Then ask to go to the, "Albergue Municipale, por favor."
If when you all arrive, there are no spaces, they will direct you to others close by.
So, with these few steps, you have overcome any concern about talking with strangers, got a cab and made it to your first night's accommodation. From here, always introduce yourself around any chance you get. Once in the mix with everyone, you will be learning from people who have been on the path for at least a couple of weeks. They will have handy information to help make your walk as enjoyable as possible.
As to walking, walk until your body tells you to take a break. Rest 10 min to 30 min, usually. Hydrate, let your feet out to breathe if they are screaming. Do what you need to do to remain happy. Then walk some more. After a few days, you will get a good idea of what is your best, most comfortable daily distance. Do the math. If you find your arrival in Sarria is going to be late, grab a bus and skip a day or so of walking so you know you will make it on time.
Questions?