fin placement

Hi Im busy building a board with a 8 foot 8" E clark blank. Ive done the hot coat and its looking great. I have 3 fins with fin boxes to fit. The two side fins are flat on one side and curved on the other. Can anyone tell me where to put them. Im just a beginner so amazing performance is not my aim! I don’t have any other boards I can look at so If anyone can tell me where their fins are or give me some tips it would be really cool. Cheers Craig