As far as leveling goes, there is a very simple method that I have been using. It farms gold as well as levels. It is done in bots so you don't even have to worry about being reported or having your normal matchmaking ElO (Does Brawlhalla even have that) tanked.
It runs in the background and can be ran for days. Currently using it to get all legends up to level 20+ for dem colors.
I was thinking of posting the method I am using but..it really is SUPER simple..doesn't use injection or anything. I don't know any sort of programing or anything and I managed to make it myself.. But I am scared if I post the method it will get fixed/nerfed.
It isn't amazing, but i have had it running for 2ish days (I would estimate around 50 hours of it running) and currently have 36k gold. Which isn't bad considering I haven't had time to play myself
If you are interested in it, shoot me a PM and I can maybe tell you my method