Yesterday I completed my 305 build and got it cranked up for the first time and when it started i noticed there was a drip of antifreeze falling by the passenger side motor mount I jacked the car up looked underneath and it looks to be there is antifreeze leaking from a headbolt it stopped after a little while so then i started the car back up and rode around the yard with it testing it out then it started again this time it was worse but after 10 minutes it stopped again. Later that day after inspecting everything i took it out for a run all was well but it started leaking again and then my check engine light came on probably because the coolant was getting low due to it coming out through the bolt can this be fixed or is the head done?

You need to use thread sealer on your head bolts i take it you probably miss that part?

I didnt use it on any of the bolts should i just ad thread sealer to the leaking bolt or will the others cause me a problem later on?

Well nothing a guarente but i would guess its very likely at some point it will cause you greif because all thoes bolts i believe go into the water jacket and if ones leaking alread how long till the others will. May take a few months maby even a year but at some point it will likely catch up with you. The intake manifold as well has bolts that go into the water jacket that again can cause you grief down the road.