It's not bad for a first attempt. The basic sounds aren't bad, the playing is tight and it sounds like you've wisely resisted the urge to put loads of crazy compression and effects on everything
The mix needs tidying up, mostly in the bottom end. The kick drum is too boomy. Try some low shelf or low cut (aka high pass) filtering to reduce the bass. Also try that on the guitars because they're boomy/muddy in the lows. It might make the guitars sound "weaker" when you listen to them on their own (solo'ed), but the idea is that the real bass beef will come from the bass guitar.
By the way, how have you recorded the bass guitars? Did you double-track them and pan them like guitars or something? It kinda sounds like that. You should really just have the one bass track panned right in the middle.
The drums are also totally mono so the cymbals don't envelop the sound as they could. Try panning the overheads left and right. I think the cymbals sound kinda weak and lacking life, and some of them sound kinda high-pitched. Perhaps some compression on the cymbals can give them some "smash" and aggression.