It's harder for junior devs. When I started, the remote junior was seemingly impossible. So my first job was at a local startup. But that was pre-pandemic, so there might be a chance now. Still, there is a ton to learn as a junior developer in a nice team, with kind senior developers present in the same room. So my advice would be to work for a couple of years in a company in your town with good senior developers, and only then try to find something remote.

As for the AngelList search, no big secrets. I would look for job posts explicitly mentioning "frontend", not mentioning "senior", not mentioning "remote US" (although a lot of those that just say "remote" are actually "remote US"). I would search for new job posts every single day. Spent a couple of hours finding new job posts and applying. As a junior, expect to apply to hundreds of jobs.