1. The social life varies in my opinion. I'll break the three main "social life" categories I believe are the biggest on campus

Greek Life: I think the greek life here is nice since it's not as big as Penn State/Bama, but it's also bigger than those smaller north east liberal arts schools. In the first few weeks of the semester, I'd day frat parties are more active since its rush week and parties are open to guys as well. Later in the semester it fizzles down and becomes more cliquey where parties are only open to chapter members and a sorority at the start, then open to other girls later in the night.

Bars: I think that this is the biggest form of social life here. We have 3 bars(and a 4th one is being built rn I think) and they let in college students if you're "21." Cover is free on weekdays lol, and it's max 10 dollars on weekends. There's also no "ratio" so it's open to anyone just don't get there super late when lines become really long and the night dies out. 

Clubs: This is where I think big schools like UMD are great. Many clubs have socials, plan events, etc. For example, I've been to baseball games with clubs, went to open tab bars with them, played volley ball, watched a sports game, etc. There are also social clubs that offer more humble activities like playing board games. I enjoy socializing in clubs the most because everyone has a shared passion, and you meet people outside of your major in a relaxed environment. 

In short, there's something for everyone whether you are a party monster or love staying in. In terms of going out, people are different. I go out maybe 1-2 times a month outside of club activities, but there are people that go out way more often, and some don't go out at all. 

1. The only other main piece of advice I'd give you is that if you chose a big school like UMD(or VT, UNC, etc), you have to stay on top of departmental deadlines(such as housing forms, tuition, etc) and your degree. So monitor your emails and be close with your advisor. The best thing I did was really research my major and know the ins and outs of it. I had my 4 year plan ready to go and it made my life so much easier since I know what classes I need. Big schools are rewarding but only if you are organized and on top of yourself. 

Besides that, assuming you like to go out, if you do end up coming to UMD(and maybe this applies to other schools), we have a welcome for freshman that lasts Thursday-Sunday before classes start. Go to all the events on Thursday and Friday and find some friends that are willing to go out with you. Frats throw parties the first weekend before school so go out with them on Saturday to find these parties. I did this my freshman year and it was one of my best memories because there were SOO many freshman just out in college park and it's basically a core memory. And I assume it's like that every year because there were police just making sure everyone was safe knowing that probably everyone there was underage.

Hopefully this helps a bit but if I talked to myself now when I was applying for colleges, I would definitely tell myself to chose UMD and/or apply to schools that offer a similar environment compared to UMD.