Time to quit? Wwyd

I've been at Whataburger for 13 months at this point. I started off being prep and then about six months in asked to learn front to get a little more under my belt. I learned it semi decently but I am still a little slow with it and sometimes have trouble hearing customers or understanding what people over the phone say. I can do most stuff but not everything. I am almost constantly doing at least something either prepping it re stocking but sometimes I see others at front just talking in the lobby and there's orders sitting to be taken to customers. I offer to work when not scheduled due to school right now. I have been mostly on prep and I think they don't really want me on front. I am not very sociable or talk to my coworkers aside from very short small talk. I have never had anyone say I'm rude but when customers small talk at the front counter my responses are usually short or very neutral. Not sure if this contributed to me not getting front that much?

I have wanted to do front when it seems like its a good turn and there's enough prep but I am told to go back to prep sometimes and that has stopped me from wanting to switch stations but I see a lot of coworkers do it...? I worked the evening shift and most are high schoolers. I'm about 2-3 years older than most of them. I see them fool around and sometimes the managers are in on it and when I ask for breaks lately I either cannot take a paid shorter break (at all) or I am not able to near end of shift. I had a manager tell me I can't after 10 get a break but other people have asked to have theirs later than when they're asked if they want to and they say yes. It doesn't even make sense because around 10 it's very dead usually unless it's Fridays. I also didint know that there was a group chat and was never invited. Whenever I tried to do gator I kept messing up in front of the OP and they told me I can't run it and I never touched it again since I'm not technically not forced to. Some employees don't like helping me but they ask help from me and I always say sure and try my best. Don't look forward to going to work and I think aside from maybe one manager they don't really like to have me around. Mistakes I make always feel blown out of proportion when am knowledged and I feel very bad.