Two things to consider:
There are a lot, really a lot of travel memoirs of the Camino, especially the Francés published already, you really need a unique point of view / style to stand out from the crowd.
Be careful, I hope your friend warns you of this also, not to fall for any company that takes your money in exchange for 'deluxe publishing packages' or similar. You can publish for free on Amazon via KDP and Createspace.
Upfront costs for indie authors are typically cover design, editing and proof reading and you can organize all this yourself, you don't need a publisher for this. If you have any questions, send me a PM and I do my best to help. Buen Camino, SY