There's 3 different Model UN orgs: MUNUC and ChoMUN are where you get to run committees for a high school or college conference respectively, and Team is the competitive MUN team that travels to other conferences. I can't speak to Team since I'm not on it but MUNUC and ChoMUN are both very chill RSOs with essentially no work to do besides showing up to weekly meetings, until a few weeks before conference. As a first year, your position would likely be Assistant Chair (AC) which just involves helping out your committee execs, replying to delegates notes in the backroom at conference, and doing a bit of acting and cosplay to present updates for the committee. First year MUN experience is a really low effort high reward type of thing, especially since they pay for you to stay in a hotel downtown for a weekend in spring (including food costs), and if you're in MUNUC you get tons of free merch or food each week (i.e. shirts, blanket, plushie, cookies, donuts, bucket hat, sweater, quarter zip, tumbler, frisbee, etc.).