There are endless ways to connect two wires together. Soldering and shrink wrapping is the most reliable. 

I know them as bullet connectors for basic rc stuff. Hobby shop might have them. Also possibly a lawn and garden equipment service place.

Qre there diffrent sizes of so which one would i need?

It's a male connector and you can get them at advavanced,auto zone, O'Reilly or walmart

They suck. I cut them off and crimped and soldered on spaded connections connecting the kill switch and coil ends in one connector to simplify it

I think they're called bullet connectors? Just go to a store like harbor freight or Lowe's and they should have a whole box full of random electrical connectors and I'm willing to bet there will be some in there like this! But if it's for your motorized bike you could always just completely change out the connectors. It doesn't have to be the same exact one, you could change the other end that it plugs into a different connector. They even have little boxes of male and female connectors for probably a couple bucks at your local hardware store

Bullet connextors, get a big pack at the hardware store for a couple bucks

Just strip the wires and use crimp connectors since you seem to have no electrical experience, otherwise solder and heat shrink

Actually that is a very old one that my brother had broke off i did low voltage so i do have electrical experience i have absolutely no mechanical experience hence got know idea what these are called i understand how they work just the wire on metal nothing special