The most common recommendations would be to get a better chain tensioner and to get a sprocket hub adapter. I would swing by my local auto parts store and get a better spark plug. Either a NGK BR6HS or BR7HS, If you want to get fancy get an iridium plug like the NGK BRP6HIX or BRP7HIX.

You also should grab some red Loctite, I like 2760 but any red should suffice.

For tools you will need 10mm, 14mm and 17mm wrenches, a set of metric Allen keys, a Phillips & flathead screwdriver and scissors if you use the rag joint that comes with the kit.

Use quality 2 stroke oil at a 40:1 mix ratio from day one and just take it easy for the first few miles. Make a habit of checking all your hardware between rides because these little 2 strokes like to vibrate things loose.

PS: be careful when installing your gas tank, they are very thin and its easy to over tighten the nuts and crack where the studs are welded onto the tank.