Gil, welcome to the forum. I haven't walked the Portuguese so was reluctant to chip in but as nobody else has yet responded I'll at least get the ball rolling for you.
You don't say exactly what type of information you're seeking or what kind of background you have. For example: I appreciate this is your first camino but are you a hiker, have you done any long distance walking? Have you done any training? Bought your gear yet?
There is lots of excellent information available here on the forum, use the search function above for whatever information you're seeking. For example 'winter packing lists', 'Camino Portuguese' etc.
Accommodation. As you say, an awful lot of potential accommodation will still be closed in February /March. Many suggest downloading the 'Gronze' app, whilst it's only ever as good as the last update it's an excellent starting point. That or '
Wise Pilgrim'. And then contact your chosen accommodation option either by phone, email or WhatsApp. Which incidentally if you haven't got it is highly recommended, as it is used extensively on Camino for communication.
Food : because so much is closed you may have one or more days where you come across literally nowhere to buy food. So ensure that you have a stash with you - useful items like (tortilla) wraps or crackers , perhaps a tin of tuna or sardines, hard cheese, cup a soup packet's, a few instant coffee packets or tea bags, a mini Nutella or a little chocolate. You might even want to consider a freeze dried meal or at the very least a packet pasta. Some even carry a metal mug and an electric coil.
I would go on, but frankly it would be more helpful for you to be a little more specific rather than me write for the next hour only for you to go - well yes, I know that!
Regardless, Buen Camino!