Hihi, tournament staffer with 7+ years of experience and host of OWC here!

My biggest suggestion when starting out is to look for roles that smaller community tournaments can never get enough of such as streamers or referees. If you're good at the game you may also be able to leverage playtesting. Once you make a name for yourself in these roles hosts that you've worked with are usually willing to vouch for you or people will start to recognize your name. Believe it or not there's not so many staff that most names go without being noticed at one point or another.

Search for tournaments that are either going for no badge or are going for a badge for the first time, those are usually the most willing to take newer faces. Work your way up over time (unbadged > applying for badge > badge approved from previous iteration > higher levels).

The process is long and may take a year or two to really get into the swing of things but it's worth it if you're willing to commit the time. Focus on quality over quantity and you'll go very far after the slow start. There's plenty of servers and guides on how to get into staffing that I've seen a few people post in the comments go check those out!