Your first project? :o
I like the blend of various elements here. Could probably do with a fade in for that under-water sounding SFX.
I'm fairly sure that, had you had better material to work with, this track would be a banger. Compositionally, I've got zero complaints.
Mix wise, lot of lo-mid noise on your reverbs. Try turning down the FX wet and hi-passing it. These frequencies tend to gradually build up and muddy your mix. There's also a lot of hi-fizz and sub noise. I can't tell if some parts of the track are clipping.
FL studio's default synths generally are terrible. I recommend some free synths like ABPL bass, AGML guitar, Headroom/Intimate Piano in the free kontakt thread, SQ8L -- I think ABPL can be loaded with your own samples if you wish, as well. Emissary amp and NadIR/kefIR cabs are free as well. Personally, I use (non-free) plugins like RealEight, Kontakt 5 with Metal Factory Drums, Ample Sound AMR2 (same company as the bass and guitar I recommended), and GrindMachine/Dominator amps, which have built in cabs.
This track was quite a journey, even despite technical issues. Liked it a lot. If you get those mix issues under your belt, I see a long path of success ahead of you!