These days there are a lot of pitch events. Not very many people end up with likes from agents/editors/small presses, but that doesn't mean it's not worth it to participate.
First my personal reasons why I participate:
-these are amazing for building connections! And trust me, you want to build your literary community!
-pitch events can help you refine your pitch for querying (and those through QM almost always ask for a 1 line pitch)
-they're fun! It's a nice break from the drama frequently unfolding on Twitter/X in the writing community (there's so much of it some days. It's exhausting).
-you can get awareness out for your project
-and maybe, just maybe, you'll actually get some interaction from industry professionals! Even if they don't pan out to anything, it's good feedback that you're on the right track
Now for my "hows" on participating:
-this first one is the most obvious - PREPARE AHEAD OF TIME!
-get feedback from betas/CPs/writing groups/etc
-make sure you know and understand the rules for each event (the hashtags you're supposed to use, how they want people to engage with posts, the hours, what types of manuscripts you should be using i.e. finished or at any stage)
-this is one that has surprised me no one else seems to do, but works amazingly for me. In advance of the event, search for the event hashtag. Find as many as people as possible who are building their lists and post about wanting to swap support, and comment on ALL of them. Seriously. It'll get you a lot more engagement early on so agents are more likely to see your pitch and not be lost to the algorithm (also, make sure you follow through on supporting theirs, too!)
Some final notes/advice:
-if multiple pitches are allowed for the same project or multiple throughout the day, do your best one first (especially if you got on people's lists as that's usually the one that'll get all the interaction)
-PIN YOUR PITCH! Agents come back to them hours and even days later sometimes and you want them to be able to find your pitch easily!
-interact with others. It'll help you hone your own skills, and you can build others up who may need it (again! build those connections!)
And, finally, make sure you have fun :)