Is there any good custom games out there I can download? Not only that but is there a way to look at other people’s file shares through the website?
Dude. You’re obviously playing a BETA. So please stop asking for Modes or filesharing… That’s exclusive for Halo 5! 
No, seriously, I don’t know good customs so far, sorry.
343 screwed Custom Games beyond recognition.
check The Halo Forge Epidemic for custom maps and gametypes, they’re pretty good, but not as good as H3’s. ironic, isn’t it?