if you guys can actually write something nice, u should play ur compositions AND covers, since its your first gig.
Depends on the gig. I personally prefer covers for acoustic sort of performances, I'm sure most people do too. Its nice to hear something you know and can sing along with, especially if its a song that generally sparks good memories. People like familiarity. It'll definitelly boost their outlook on you. Covers are the safest choice. Playing your own music can be risky - if they don't like it, it lowers their impression of you. If you stick to covers for a while and build good representation, then you can bring out your own music and see how it goes. If they don't like it, you have good representation to fall back on. Of course, you can make a good balance by maybe playing a song or two of your own, but depends on how long you're playing for. Good luck!
See its just me and a friend of mine playing acoustic guitar and singing, we would like to do some silverstein stuff, aaron lewis, and stuff like that.
Definitely go in with some covers, and maybe towards the middle or end, toss in 1 or 2 of your own. Its good to play your own stuff, just not right away or all the time.
"Because hoes don't trust anyone.. especially me."
acoustic opening for a metalcore band...? Im not well versed in that sort of music, but Id stick with anything acoustic from that genre or time period. Depending on how lenient and tolerable a crowd metalcore fans are, I'd carefully limit the variety of songs you play. I'd ask metalcore fans specifically what they would suggest. Best of luck to you!
Personally I would prefer to hear some covers but a few of your own would be great too.