Welcome to the forum.
There is always plenty of advice here. Sometimes too much!
Firstly, check the FAQ's. They are a mine of information. It might take a couple of hours but you will know so much more.
Secondly, follow the active threads.
When you have specific questions there are plenty of folk who will answer them, probably giving you alternatives as the Camino is an art not a science.
The quick things ot say if you want your Camino to be happy.
1. Get your boots or footware well broken in. Decide what footwear you are going to wear. If you turn up in new boots you will get blisters.
2. You should carry no more than 10% (not 25% as originally posted) or your body weight and 10kg max. Remember you will have to carry water and if you want to carry some food, that adds to the weight.
3. If you do some training you can reduce your exhaustion, keep down your pain and will enjoy the Camino all the better for it.
4. If you want to collect a Compostella then you must walk the last 100km, which means from Sarria to Santiago.
5. If you can learn some Spanish phrases, especially greetings, food and directions (the Camino is wonderfully waymarked but there will be times when you will want to explore places) that would help.
Otherwise, read the FAQ's and come back to us then.
Buen Camino (Good Way)