This is not very straightfoward so here are some adive for people to navigate the game better.
To get a job : Go to the diner in the motel, and speak to the manager by clicking on the top left of the screen. Do this early on, work often, improve your relationship with the manager and ask for raises, check the "personal status"' page on your phone to know it's time to ask.
You will need money to jump to the next dirty steps. For exemple you can buy a subscription for adult content on the TV, so I paid and watched an adult show with the mother, which unlocked masturbation stuff to unlock with her. Which then led me to watch porn with her. And so on.
Rotate the girls in your room, check the "Personal status"' in the phone and check the conflict bar, if it's almost full it's time to change girls otherwise you are headed for a game over. You can progress way faster with a particular girl by sharing a bed with her
Make sure to chat and improve your relationship with every single character in the game. Even guys. To do so, "chat" everyday and ask "how they are doing" if it's available, discuss their interests and so on. For exemple improving your relationship with your father will eventually unlock a hot chick at the bank.
Improving your relationship with the motel owner at reception will unlocks options in the motel, like the pool. You can also ask her to change your room to a one bed room so that you and the girl in the room can raise your sexual tension by sleeping next to each other. Improving relationship with most "outsiders" (police, atorney and so on) will unlock info they would not share otherwise with you, allowing to progress with the intrigue.
Don't spam the "find job" function on the phone, it's a waste of time, until you are quite far into the game (at least it gave me nothing so far).
If you are stuck in the story, check the friendship level with the character, if it's not best friend you can keep going and will unlock something.
Masturbate in your room if a girl is coming home soon, she will walk in on you and your sexual tension if you are close enough. If the girl is in the room, masturbate this time in the bathroom and there is a chance to trigger a scene that will raise sexual tension.
If there is still more dirty stuff to do with a girl, check her sexual attraction to you. So far the highest level I reach is sexually attracted, I think there is a higher level with sexually fascinated.
It's better to ask the mom (when she likes you enough) to switch to a single bed room than to ask the receptionist as it is free with the mom!
That's all I can think of.