1990 Lexus LS 400 LOTTA PROBLEMS " LS400"

Hi. I have problems with water getting In. Right in front the passenger side headrest, leaking down windshield and peeing on my girl friend when shes in pass seat lol. Another thing CD player stopped working. It opens up and I am able to change CD's, when I press CD on the radio it goes to FM 2, press tape it works (lately giving me hard time) ETC. Also check engine came on after I had the starter changed (and many problems) Car wont start or I have to keep giving it gas, but it chocks and engine knocks, then it starts taking gas after about minutes but will shut off unless I give it gas for about 7-8 min, Heat stopped working after starter changed. I guess figuring out how to get the code for check engine. Also where is the gas filter?

My dad keeps telling me to sell it, but 1. I cant afford another car. 2. I love my Lexus I just want all the problems fixed.

Thank You
Sami K