No one can explain, on a forum, what to do to your engine. Whatever anyone says, there is always a lot more.
You likely should go about the business of engine building, backyard, front yard, or garage, with the same sequence as you would, if you wished to become a heart surgeon.
You would not start out by cutting out someone's heart, and trying to figure out how it worked.
1st thing you do is study, then study some more.....as to how engines work. Look up (Google has lots of this stuff) about air and fuel flow, and their relationship.
How do cams do, and how do you make choices between them.
Take a machining class at a local vocational hi-school. That is a basic necessity.
You will need a valve grinder, mill, lathe, geared hone, measuring tools and other "stuff"and plenty of patience.
Engine building is not a hobby.....and a hobby is not engine building. Engine building requires considerable knowledge of the makeup of material, a LOT about
air and fuel flow, and their relationship to compression, bore/stroke ratio's and a ton of other stuff.
This is not "easy" stuff. Well....I've got to go now, cause I need to close a deal on another, larger lathe than I currently use.
Oh yes....did I mention a sizeable investment in tooling? It IS satisfying tho. Go for it!!