How to build a reliable trend trading system? Let's discuss

I resigned yesterday, due at the end of the month, I want to do trading full-time, but I don’t know how far this road can go?

I have been unable to set the stop loss in the transaction, how can I do a good stop loss?

Fund management has always been a headache for me. May I ask you guys, how can I do a good job of position control?

How to determine whether your trading style is short-term or long-term?

What is a perfect trading system? Or is there a so-called perfect trading system?