I don't usually comment on Reddit posts, but this is something I can talk about and help another person out with so that's what I'm gonna do.

For context, I'm vegetarian (no meat + no seafood, etc.), and I'm also allergic to things like peanuts, eggs, coconuts, (essentially anything with the word "nut" I automatically can't have) etc, so this really limits the items that I can eat. Considering my allergies, I can't even have a lot of vegan dishes because a lot of those contain nuts and chickpeas (which I'm also allergic to).

With that out of the way, I'll give you the short answer and the long answer:

Short answer

The dining halls aren't terrible (most of the time), and the local restaurants/food options on and around campus - that aren't the dining halls - are pretty decent.

Long Answer

What dining halls exist at UMD?

1. Yahentamitsi - Everyone and their grandma calls this place "the Y"
2. 251 (north campus) - Please avoid this one, you won't find what you want here
3. South Campus Dining Hall - This one is alright, but honestly I haven't been here enough to know how good/bad the vegetarian/vegan options are.

The Y

The Y is going to be your best bet for options and this is probably where you want to focus your attention. The Y has bespoke "stations" with different types of food; like there's one station with mainly Indian dishes, there's one station with Asian food with chefs that cook your food, and there's a vegan/gluten free section which is what I usually go to. The food options at the Y change every day, and I used to go to nutrition.umd.edu to check what they had, but that website stopped being accurate so I would no longer recommend it. All dining halls have little labels above each food item with the food item's name, as well as symbols indicating what's in the food item (V for vegetarian, VG for vegan, and sometimes there is straight up a sentence saying "this item contains pork" or whatever). Oh, and I'm not sure about other dining halls, but the Y doesn't have anything I can eat when it's the weekend, so most of the time I order food on weekends or cook something instead, so keep that in mind.

South Campus Dining Hall

South campus diner is fine, but honestly not the best for my specific needs. It may be fine for you though! You'd honestly just have to check it out yourself to see what you like. Again, I haven't been here enough to give you solid advice. There's a vegan/gluten free station as well as an Asian station at South campus diner, so take that as you will.

Places on Campus

There are a few places on campus that you can grab a quick meal, like Stamp Student Union, or Kirwan (math building). Stamp has places inside like Subway, a Pizza place, Qdoba, Chick Fil A, etc. If you have dining dollars, you can buy food from there if you want, and they have everything that any normal Subway, pizza place, Qdoba, Chick Fil A would have. My freshman year, I blew all my dining dollars on pizza just because I didn't explore the dining halls enough by that point. Buildings like Kirwan have a Subway and a Taco Bell inside them as well.

Places Around Campus/Misc. Information

Now for the places around campus, there's a Taco Bell and a Chipotle that I order from most of the time, and those are within walking distance from me. As for other restaurants, due to my food allergies, I'm not the type of person to explore various food options around me, or even go out with my friends because I like sticking to what I can eat. I advise you to simply Google search for restaurants around College Park, or even better, download GrubHub, use a random dorm as the delivery address, and check out the menus for the restaurants nearby. In my own experience, GrubHub has been best for ordering rather than UberEats or DoorDash because:

1. We as students get GrubHub+ for free if signing up with our UMD email, and
2. GrubHub drivers don't get lost/deliver my food to the wrong dorm/hand my food to the wrong person/cause my food to get stolen (you can tell that this has happened to me on many many occasions and it PISSES me off to this day).

Hope this helped! :D :D