I Need help with my 1995 Chevy Cavalier Z24,actual mechanics please or people

[That guy]

that actually know cars please!? I just got a 1995 Chevy Cavalier Z24,I love it,it handles amazing,brakes unbelievably well,looks awesome,but I have a possible problem.Its my first car,and for $800 and 130,000 miles,in good shape,what could I lose?So we bought it today,drove it around,it runs fine,drove it maybe 50-75 miles,and when I got home,we notice that the 2.3 liter quad 4 is extremely loud,leaking air through the vacuum hoses,and the exhaust rattles bad at low rpm,now at around town(20-40 mph) it runs fine,no excess noise,at highway speeds (50-75) still perfect,but at a low rpm (800-2500) idle/slight gas,it is very noisy and rattles.My dad said it was terminal,just dont run it hard and it should last long enough for a 1st car,and it needs an engine,but I love the car,and had so many plans with aftermarket parts,i want it to run perfect.so if anyone has had a 1995 Z24 with a 2.3 liter quad 4,and knows what the problem is,or has worked on them,please let me know,I was really thinking it was just needing a tune up and new hoses,but if its terminal,or needs engine work,tell me what it needs or whether it could work with a 2.4 LD9 twin cam.Thanks so much,its either this or a 91 Z34 Lumina,and I cant find anything cheap for a Z34.Thanks so much,your help is really,really appreciated.