Hello! Thank you for playing Lucky Days!
As for tips in getting the $5000, make sure you always wait tables and always get $20 for each scenario, if you get anything less, even $15, you won't make the goal. One strategy would be to save before every choice to make sure you get the $20 since there's no rollback (because I was bad at game design back then, I'm sorry;;)
I wish you luck! And another tip: When you get all the endings, if you play one more time, you'll get to see a bonus "date" scene!