Hola Marica and welcome.
There are whole threads devoted to this subject which you will find as you get accustomed to this forum. Shoes/boots; socks; blister care etc.
To help you start this is our way of caring for our feet.
Start the day with dry feet. Terry powders his with 'Fungusol' sold in Spanish farmacias and recommended to him. I don't powder mine in the morning but do so at night. Wash and dry your feet well each night. Check for any rubbed places and use a plaster next day if necessary. We do not use Compeed!! Others love it.
We wear 3 pairs of socks to prevent blisters - the middle pair take all the friction. All should fit without being overtight or wrinkling.
Very thin inner pair next to the skin. Make sure thay are a good fit and smooth them before adding a mid weight second pair. Again smooth them out before adding the final thickest pair. Again smooth them out and put on your chosen boots/shoes. The inner liner socks are washed each night. We have 3 pairs each. The middle and outer socks we have 2 pairs each as they do not need washing much due to their make. (This all includes the ones we are wearing)
We like lightweight leather boots which come just over our ankles for good support. They must be bought wearing a full set of socks for a good fit. It is best to try boots later in the day when your feet are warm and have 'spread'. Leather is breathable and can be waterproofed. You should have wriggle room for your toes. A good shop will help you with fit.
If you feel a 'hot spot' while walking
stop right then, not half a km later. It is a blister starting. Take off your socks, check out if anything has wrinkled and put a plaster over any red place. Check both feet. Replace all footwear carefully and carry on.
(I had to do this right at the end of our Camino.)
You are so right to ask questions about foot care as 'happy feet' are so important.
Then comes the importance of a good fitting pack........
Buen Camino