So my first shot at making a mold. I know what I did, gelcoat was too hot before I mixed it and I also let the plug sit in the sun for a while. My question is, can this be saved? Or should I just start over

It's hard to tell from the pic, but I can't really see a whole lot wrong with it other than the poor coverage. If that's the only problem then just do another coat of gelcoat and carry on.

If there's any pre-release or bad porosity from the gelcoat being too hot then you'll want to start again. Realistically, you may just be better of starting again regardless - it may be fine and you waste 200g of gelcoat, but if it isn't fine and you carry on then you waste 400g of gelcoat, plus a whole lot of resin and fibreglass... So sort of your call on whether you think there are problems.