[Heel n Toe]

I'm not sure if there are other brands, but Carrera Go (1/43) is very popular worldwide AFAIK and isn't going away anytime soon.

And with the smaller size (but it's larger than H.O.) you can fit a lot more track in a smaller area, and can make a more interesting layout than if you had 1/32 or 1/24 and limited space.

Also, Carrera sells all manner of extra track, etc. so you should go for it. I've found extra track packs at Hobby Lobby and at least one other local hobby shop.

You can find it online, too... ebay, Amazon, Electric Dreams.

https://www.amazon.com/Carrera-Extension-Set-Expansion-Digital143/dp/B0002FQKNE/ref=sr_1_9?crid=1Q8F7RPMIJB3F&dchild=1&keywords=1%2F43+carrera+go+slot+cars&qid=1587622610&sprefix=1%2F43+carrer%2Caps%2C187&sr=8-9

https://www.amazon.com/s?k=1%2F43+carrera+go+slot+cars&crid=1Q8F7RPMIJB3F&sprefix=1%2F43+carrer%2Caps%2C187&ref=nb_sb_ss_i_1_11

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR6.TRC1.A0.H1.X1%2F43 +carrera+go.TRS0&_nkw=1%2F43+carrera+go&_sacat=0

Electric Dreams even sells parts
https://www.electricdreams.com ....... https://www.electricdreams.com/Shop/slot-car-parts-c-3/carrera-go-143-scale-parts-c-3_660/

Lots of info of all types on YouTube
https://www.youtube.com/results?search_query=carrera+go+race+track