All questions I've been getting are answered with this video. Showing what goes into the making of antweight fighting combat robots. I was only finishing recovering from flu when this was done, so the execution may not be great.

Basic parts list:

Mini metal gear motors (500rpm, 6v):
https://www.aliexpress.com/item/Free-...

NanoTwo V3 Dual ESC:
https://nutsandbots.co.uk/product/nan...

Wheels:
https://shop.pimoroni.com/products/po...

Turnigy nano-tech 7.4v 180mah Li-Po battery pack:https://hobbyking.com/en_us/turnigy-n...
Battery charger:
https://www.ebay.co.uk/itm/iMAX-B6-Di...
If you’re new to Li-Po batteries be sure to read both battery safety guide and charger setting for safe use and charge.

Radio gear (2.4ghz) I’d recommend is anything Spektrum with DSM2 or DSMX technology on a LemonRX 6ch DSM2 receiver.
If a new one goes out of budget some second hand can be found for a good price.