Used to be giving bjs at the nightclub. Could get up to 30k in a weekend depending on luck. Dunno if that's still possible now since it seems to be the same as the community centre which is a lot less money.
Ig you start in the holidays then you can do the Starlets, but it's a lot of training needed to qualify and it ends around October so it's limited time, can make good money though.
Modelling is good long term, but it's not a huge amount of money to start and you need a fake ID. Once you have high skill and rep it is a good chunk of cash for little time per week. Works well with doing Running and Kick Boxing in the city for extra cash per week and sports rep which lets you do Fitness shoots for more cash.
For the test release I had a start that made starlets reasonable (jock dancer), I did Starlets to fund modelling and sports. Starlets just ended and I'm at ~250k in the bank plus laptop/guitar/camera/recording gear/implant. Seems fine.
edit: starlets is probably ~5k per week, modelling is like 2k per week to start going up to 6k+ with skills and more with special jobs, running/kickboxing is like 1k per week to start and goes up to like 3k per week by the time school has started. Beating a mugger is ~1-2k and takes almost zero time, so it's very strong.