Depends how accurate you want to go. Movie!Thor or Book!Thor? There's a difference. If going with the comic book version, then which one? Different artists drew his clothes differently.
The most accurate looking, but time and labour intensive, for movie!Thor is to make the sleeves with scalemail
. You can look up how it's done on Google. It won't be terribly comfortable, but looks the closest to what Chris Hemsworth actually wears in the movies (and he did say the metal sleeves were awfully uncomfortable in an interview)
The vest and pants you might be able to find on military clothing supplier websites. The chest armor can be created with craft foam (this is one of the most famous tutorials
). Cape is really just a rectangle of red fabric as long as you are tall, and attach it to the chest armor with your favorite method.
Boots, I don't really know. Unless you get lucky and can find knee high boots for guys (this is hard, my bf has tried) then I'd suggest boot covers. Coscom has lots of tuts for those. Maybe a plainer pair of guys' goth boots (big brands like Demonia will have them, but could cost a lot) without platform or risers? My bf got old equestrian boots from his dad who used to be a mounted cop, but they really weren't ideal. Riding boots are not meant for walking in.
If you're not good at making things yourself, the other option is to find someone to make it for you. There are lots of commissioners on this forum. Just beware, it will cost more than making it yourself. So it depends what sort of budget you have. When doing it yourself, you're only spending money on materials and your time. When getting someone else to do it, you're buying the materials AND paying them for their time. Lots of people around here who don't know how to make things successfully commission their costumes and props, so it may be worth it for you to look into.