The easiest way would be a PayPal link. Put a button somewhere on the site. I'm not familiar with SquareSpace, but I assume there's a widget or something for it. Here's a YouTube search.
If you don't have PayPal, it's one of the best platforms for sending and receiving money if you're going to be moving or have dual citizenship. PayPal works everywhere. There are others, but I haven't used them so I can't comment on them.
About the implications of income reporting, IDK how to handle that. My first inclination is to incorporate a non-profit entity, but the paperwork can be expensive and reporting a headache. Nevertheless, you probably should research incorporating in one country or the other. Overall, though, I don't know if you'd take in five dollars or five-hundred bucks a month from donations, so it may not even be a concern at this stage.
I'd say get OBS Studio
(it's free) plus maybe an inexpensive microphone and just start podcasting. OBS Studio is popular and capable, with plenty of tutorials on YouTube. It doesn't need a ton of computer power to run - I had an older release on a 2014 bare-bones all-in-one and it worked for most things. OBS does have a learning curve but, again, it's free.
I've never streamed myself, so I can't help you set things up. But a cheap, dedicated microphone will probably make the audio quality a ton better than a built-in mic if your computer has one.