You may possibly have the valve timing off, if the gears did not get put back on properly.
You need to put the engine back on TDC of the COMPRESSION STROKE, so that both of the valves are closed. If the valves are part-way open, then you are on the intake stroke, and that is not the correct TDC. So, get the engine there, and you will be close. But unless you use a dial indicator and degree wheel, and use them to centralize the location in the "TDC dwell" of the piston, you will only be within maybe ten degrees. So, you have to know this. For setting the valve timing, that's close enough.
Anyway, you get the piston there at TDC, and don't move it after that. Take off the timing cover carefully, taking note if any cam shims fall off, and hopefully noting where they came from. Then look at the cams and the crank pinion gear. The dot on the crank pinion gear should be at about one-o'clock position, and the exhaust cam dot aligned to it. Then, look at the two cam dots where the cam gears touch, and they should be aligned. Even if they are not exactly perfectly aligned, as long as they are definitely on the same tooth/valley alignment, then they are okay. They might be a very little off if you didn't get TDC exactly, which you probably wouldn't without a dial indicator and a degree wheel.
Then put the cam shims back on where they were, and you can put the timing cover back on.
Now, to do the timing, you use the "stick tool". If you don't have one, you make one. It's a stick, like the wire you are using, but it's rigid, and it has a guide that screws into the spark plug hole. You can make this guide by knocking out the center of an old spark plug so that it has a hole down the middle, and all the porcelain broken away, so that only the metal part of the spark plug remains, and it's flat on top. Get a suitable "stick" made of rigid material, and with your piston at TDC, put it into the hole so that plenty of the stick still pokes out the top at TDC, and mark it to match the guide at that location, and that is TDC. Then, move the engine in the backwards direction from the way it would normally run, and find the place that the piston is 0.8mm(1/32") below TDC, prior to reaching TDC(NOT after TDC). This is the 0.8mm before TDC that the manual talks about. Leave the engine right there, and don't move it.
Then you can do the ignition timing.
Set the points gap first.
Then do the timing.
It depends on how accurate you found TDC, as to how accurate your ignition timing setting is going to be. You may have to make minor ignition timing adjustments if it doesn't start.
My "rule of thumb" is that if the engine kicks back but doesn't start, then try retarding the timing a little bit. And if the engine is not kicking back and doesn't start, then advance it a little bit and see if it will start.
It should start in a few kicks if it's right. You don't have to wear your leg out trying to start the bike. If it doesn't start in a few kicks, then check your adjustments.