Modern Buddy

I'm a new scooter owner, I have a 2016 RH50 3k miles.

Bought it used, first 3 weeks I could electric start, then I had to kick start.

Then eventually it didn't start even with 50 kicks. I changed the spark plug then it was kick starting for 2;weeks.

Now nothing will get it on. I have a jump starter, I attached it to the battery and I hear it trying but it won't start. It has fuel and oil. What cannot be.

Technically, this bike will run with the battery not even connected, with kick starting. So if yours isn't, you may need to look at other problems. When you took out the old plug, was is completely crusty and black? What does the current plug look like? If it's also nasty, what kind of oil are you running? If you're running super cheap 2 cycle oil, you may just be fouling plugs way ahead of schedule.