Glasgow Model Car Club

Hi there
I am looking to have a go at the RC racing hobby and picked up a built but unused Schumacher Cougar Laydown kit. Looking for some advice. I was looking at putting in a Hobbywing XR10 justock G3 with Justock G2.1 motor combo.
I intend to come along to EK when you meet back up but looking to at least fit out car if not setup.
The motor comes in a multitude of variation from 6.5T up to 21.5T I believe. Any advice on which would be best to start with (was considering 10.5T) or indeed if better option on similar price level.
Any help appreciated.

Ps. Currently practicing with a Tamiya tt02b 4wd to get a handle on the basics.
Thanks

EK is a big track 10.5 is a good starting point but some go as low as 8.5T I would suggest trying to pick up a motor between 8.5T to 105T to get started, going to a quick motor too early will be difficult so but 2nd hand then when you feel more confident upgrade. As always it is worth getting down to the club and speaking to people but int's winter we will be back up and running March/April, we do race indoors at times too.