I'm dumb when it comes to types of wood, I can't really tell what is what. I can only tell that they're trees, lol.
Well, one of the difficulties is variations in species from one country to another, and from climates and regions. There are many different species of Willow tree, and many variations on how they can look depending on where they grow. There are guides for telling what kind of tree it is - though some trees are only easily recognisable by the leaves, so it's tough in winter. Ash has a distinctive bark though. Just google trees for your country or region. If not just keep hacking at trees until one works
Also I would like to craft a bow, but that would be really difficult for me, I have no experience with woodworking, but I'm interested, and willing to learn.
For a bow I would guess you would need a soft wood, one that's really flexible - it'd need to start dead straight and then you bend it to add the string. If you make it out of something like oak, it'd be impossible to draw and would snap even if you could. Willow might work ok. I read somewhere that longbows were made out of yew, but I would guess that you would need to carve up the whole tree cos the branches don't grow in a nice straight way. I'd imagine you could make a bow just with a straight bit of willow, put notches in it and add some string. But it wouldn't be very powerful and probably not too accurate. And you'd have to figure out what string to use.
I think learning to make a bow would take a lot of time
But finding a 180cm straight branch is a bit difficult. Maybe I'll need some planks, or I don't know.
This is where stealing from copsed woods is good. The trees are all young and the farmers get them to grow up straight in clusters so they make easier to use wood - perfect for what you want. In a wild forest it's going to be harder to find a perfect branch. Look for young trees.
And planks are ok for making a sword I would guess, but remember that most of the planks you'd be able to find will be crappy MDF or building material, not proper wood. Actual timber is quite pricey - they only use it in stuff like expensive floorboards or posh furniture. And for a bow it'd be absolutely useless.
And @Mattressi, yeah it's true that sneaking onto property is illegal, but the way I see it it doesn't really count when their property is big enough to have an orchard in it