16yrs old, first car advise?!

I don't know what's done to your 318 but 4bbl headers and xe262h comp cam is said to make 282 hp @5000 rpm add gears stall,maybe ported heads or EQ's can do a lot.

Top end makes power and bottom end (cid) picks the power band so you can add top end parts that will work with a 360/408 later on.

That's how I plan to do it.
Port my heads then maybe eddy heads then cam down the road and maybe a 408 bottom end not the hugest fan rather big block (love trick flow heads) but is a big cost to get to the same place.