Oh boy!!!
Ok, you could have several things wrong, but you need to know how to explain exactly what's going on.
If you do not know what "idling" is, how can you explain what the engine is (or isn't) doing? The best way to learn is to try and descibe the problem, include pics or a video if possible, learn the right words for what part is what. Please try to understand that it's difficult for someone to try and troubleshoot the problem based off of what you are saying and that sometimes what people say doesn;t make sens if the right words or terminology isn't used.
If you do not have a pull start on your engine and you are able to peddle start it (peddle bike to speed, let out clutch and the engine starts) then that tells me that your clutch is adjusted right.
Now, if you give it throttle(twist the gas) and the engine does not rev up at all, then you probably have the slide installed in the carb wrong. The slide is the little barrel shaped peice inside the carb, under the top cap that the throttle cable hooks to and slides up & down when you twist the throttle.
The slide can go into the carb 2 different ways, but only one way is correct.
If you pull the slide out of the carb (by unscrewing the cap on top of the carb and pulling it out) the slide will be attached by the throttle cable. the cap, slide, needle, cable and spring will come out all as one peice. There is no need to disconnect the cable or anything else from this assembly
Now, look at the slide itself closely and you should see that it will have 2 notches in it at the bottom (a long slot and a short slot).
You need to put the slide back in the carb so that the short slot is to the left side (while sitting on the bike looking down at the carb) and the long slot should be on the right.
The long slot has to line up with a little tiny pin that is cast into the inside of the carb. and the short slot has to line up with the idle adjustment screw.
Slide the slide back into the carb and concentrate on getting the long slot to line up with the little pin. You can turn the slide as you lower it until you feel the slot find the pin. Also make sure that the needle is in the center of the carb (that's where the main jet is). The slide should go back into the carb easily with very little resistance. It should be a precise fit, but you should still be able to slide the slide up & down easily. All you need to do is get the long slot lined up with the little pin and the idle adjustmet screw will automatically line up with the short slot.
now, put tighten the cap on top of the carb by hand...do not use pliers or anything like that because you can distort the carb body and/or strip the threads.
start the engine and adjust your idle screw. (The little screw with the spring around it on the outside of the carb on the left side. Screw it in to raise the idle, and screw it out to lower the idle.) Set it to where the engine is ticking over nicely and not revving too high. You want the engine to sit there and run on it's own at a fairly low r.p.m. "pop-pop-pop-pop"
If you have the slide in wrong, you will not have any throttle response (engine will not rev up when you twist the throttle) or the engine will be stuck at wide open throttle all the time and revving like crazy.
I am assuming that you originally put the slide in the carb because the older n.t carb versions came with the carb partially unassembled. you had to hook up the throttle cable to the slide and then put the slide, spring, and needle in the carb and tighten the top cap.
from what you are describing it sure sounds like you have the slide in wrong.
or, you have way too much slack in your throttle cable.
The best way to learn about this stuff is to ask questions, and then tackle fixing the problem yourself.
IF you put the slide in the carb wrong, don't worry this is a very common mistake, and a very simple fix.
to check if you are getting spark....remove the spark plug from the engine. Snap the spark plug wire back onto the top of the spark plug and rest the spark plug on the top of the engine (the cylinder head). now, turn the rear wheel with the clutch engaged (so the engine turns over) and watch the tip (the electrode) of the spark plug (the end that goes into the engine). you should see a nice blue-ish white spark but it will not be constant...it will be on-off-on-off-on-off.
It will be a small spark and sometimes it's hard to see if you don't know exactly what to look for. But, sometimes you will hear it go "snap-snap-snap".
If your engine starts and runs, there really is no need to check for spark. you either have spark or you don't and the engine won't run without it.
BUT in some instances you could have a very weak spark that looks good, but is not strong enough to make the engine run.