I usually just play on default settings (arcade) and single race or qualifying to get my best laps. Is Arcade mode standard? or do i have to change it to sim?

Doesn't matter. If you're going for best lap it can be done with any settings in any mode.

Good to know. I'm looking to get back into this in the summer (I'm the one who made the categories a few years ago) and it's cool that there are a bunch of runners now.