So basically here's what you need to be aware of:
If you end up at a top-ranked place (RG) top 1-35ish you will have younger kids in halls. These tend to recruit more high achievers who tend to take the classical route to education.
For example I attend Nottingham uni and am was 27 when I started.... now 28 (2nd Year) and I have no issues with it at all, but ultimately decided against living in halls first year and went for self catered private accommodation very near to campus. Partially also because its hella expensive, and it also tends to be quieter in 2nd year private accommodations and frankly cheaper. Would I have been fine in Halls yes, and frankly I'm now doing my second year abroad in Malaysia and am living in halls and all my m8s are 19-21 lol. Its actually pretty fun being around young people, ultimately your older but not nearly enough to be too old. I can still relate to alot of what's happening.
If you are going to a lower ranked place you will obviously have more mature students and halls will be more mixed. Tending to mid late 20s and there's its more normal.
My tip would be ask yourself,
Do you need to party in first year? Is it your focus... Then you definitely want to be in halls.
If it's not your main focus... The best place to hang out consistently is actually the library, that's where I ended up making the most useful friends (3rd years) who ended up teaching me how to university lol.
Ultimately you will make friends on or off campus. But your not too old for halls at all.