First time builder, needs lots of assistance....please help

Alright, to start out, ive been researching on this site for a while and yall are great, an seem to be very very helpful, so hopefully you can help me out. I have 2 cruiser bikes, a 25 cc weedeater engine, and a centrifugal clutch. I will be making te shaft for the clutch on monday. Anyway, im throwing around ideas about how to set up the drive train, and i was thinking of making it go from engine to jackshaft (engine turns counter clockwise) using a belt (centrifugal clutch has a pulley on the end) then on the other side changing it to chain drive, going down to the pedals from there. The laws in ohio are: no more than 1 brake horsepower, no larger than 50ccs, and it cant be able to go faster than 20 mph on a flat surface. I want to hook the engine up to the pedals so i can shift with the engine driving it. Also i cant seem to figure out how to make the pedals turn independently of the engine. I have to have them on the bike and working to make it street legal without getting a motorcycle license. Im 15 and know basicly nothing about gear ratios so i need some help there too. Anyway, thank you all for taking the time to read my rant

Saw a bike in a video made from a kit that had the engine going directly to the wheel with a second sprocket on it. Im wondering if that would create a lot less drag on the little weed eater engine. Worst case scenario i can weld a sprocket to the centrifugal clutch i have and use it that way

So a little update here, the bike is a kulana moon dog in orange that i bought maybe 6 years ago, i put a breather filter i bought from advanced auto on the other day, and i want to make a straight pipe or possibly buy an expansion chamber and extend it so its at the back of the bike so i wont smell like exhaust, i have my throttle hooked up, may need some tweaking as it might hold the carb away from the intake a bit, i can grind it down a bit if needed. I have attached an 18'' rim to my rear wheel as a pulley and am currently searching for a 3/8''X65'' belt for it, then im going to final mount the engine and locate a frame mounted motorcycle tank