Can't control the handlebars. They wobble.

'year make model' of the moped motorcycle please?

First check the tire-pressure, then the fork oil; see if the wheel has a loose bearing play.

Speed Wobble - When The Bike Shakes Its Head - Cycling ...

cyclingtips.com.au/2011/.../speed-wobble-when-the-bike-shakes-its-head...

Speed wobble is the term used to describe a quick oscillation of the handlebars ... 2 A scenario seen relatively often is that the top tube of the bike is under-built.

Road Bike High Speed Wobble 1st person view ( Shimmy ...

? 1:27
www.youtube.com/watch?v=hMNFS2ap3fU

Jun 23, 2014 - Uploaded by Aurimas Petraitis
Road Bike High Speed Wobble 1st person view ( Shimmy ) .... causing my bike to be so twitchy on descents ...

you have to tighten the screws, when it is assembled it is done using the hands and no tools are used to tighten anything, do not ride it until you fix it or someone is going to get hurt

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/tony_a41fa0b801734e2f

Google this...

"how to adjust a headset bicycle"

These types of questions are best served by search engines and yield immediate answers with video.

Battery not holding its charge if you rely on your bike for transport then just buy new battery as this will never get better just worse and more unreliable it will even not start after you have ridden only few minutes ago eventually
If you want cheap fix then hook up to battery charger few hours before you need to use it but this option would annoy me after first few times personally just get new battery ASAP

take a riding course... the instructor will tell you to push the handle bar to the opposite side you are turning when running about 30mph and you really dont turn the handle bar when turning at a high speed. in low speed, handle bars should not be very stiff. maybe check tire pressure.

Why in the world are you riding with the bars wobbling?!? Get your bike to a Honda shop right now!

Is it the bars or the whole bike that is wobbling? You could have loose spokes in your wheels, the bike could be out of balance, the bar tree may be coming loose...right now this bike is an accident waiting to happen...take it to a shop NOW!

Check your brakelight wire and make sure switch is letting light go off. There is a power drain causing your battery to go dead. Also if you have any accesories make sure they don't use power when bike ignition is off. :)

Construct shims from aluminum (soda / cola) cans with scissors. Be careful not to cut yourself, sheared aluminum is very sharp. After you have cut a wide strip of aluminum, wrap it around the handlebar and put it between the handlebar and the clamps. This will increase the diameter of the handlebar and allow your clips to exert more pressure on the handlebars making them tighter. Try not to leave any aluminum exposed after fixing it; it's sharp.