What would be the best way to go statistically

videogames4life

For a Player that is a Half Ork Great Weapon Fighter because I started out choosing 18 Str 12 con 18 dex 10 10 10 and right now Im level 14 with plus one to Str and Dex what should I do with my other 12 points I get when I reach level 20 through 70 should I keep investing in Str and Dex or would that be the stupid thing to do? and should i level up all my main stats for what I am and that is a Half Ork Great Weapon Fighter and try and get Str Con and Dex as high as possible together? Thank you :-)