For the bottom you could get some gel coat resin ( which is what's on there from the factory). This is probably what a marine shop would use.
I prefer Epoxy, some micro ballon filler (thickener/anti-sag) and some black gel coat coloring. Epoxy doesn't absorb water like polyester or vynilester resins. Don't buy the cheap stuff.
You can also use JB Weld and some black coloring added in a pinch.
JB Weld will be the cheapest and quickest fix. You don't really want water soaking into the glass fibers and resin.
Depending on how severe the damage on the hood corners, you can use epoxy and some fiberglass matt.