Slipper would def be worth adjusting first! It should be loose enough that it slips for the first few meters of the cars travel when you use full throttle from a stand still. If it's too loose though it'll slip all the time, heat up, and polish the slipper pads nicely. Not the end of the world, they can be replaced, but not ideal!
The slipper will make a high pitched squealing noise when it's loose, listen out for it as you take off.
For reference, what sort of motor/speedo are you running?
If it wheelies that easily, turning down the punch on the speedo might also help, and there's also throttle adjustment on most transmitters as well. These might also help if your still struggling to control it smoothly!
Something else to bear in mind, weights aren't there to keep the front wheels down from take off...they are there to help generate grip, and balance the car. Lipo batterys are soooo light that most/all cars benefit from decent weight distribution to gain the best grip and control while racing.
Welcome to the forum dude!