[TurboLaser4G63]

hey guys I have a 79 trans am with the pontiac 400 in it. After spending over a year and 200 hours of bodywork, the final paint sprayed interior done. I started her up and immediately new something was wrong, it was backfiring through the carb and making all kinds of terrible noise. After pulling off the valve covers i noticed staggered rocker arms and a pushrod missing, it had worked its way about half an inch over ont he guide plate destroying that before it snapped. The lifter appreared to be gone, upon removal of the intake manifold etc, the missing lifter and pushrod were in the valley. My neighbor is a pretty big muscle car buff, I know absolutely nothing about these things, learning as I go, he suggested buying new cam and lifters, high energy pushrods, and the new guide plates,
Anyway my question is, should i be okay with just these new parts, I discovered that the reason for the broken pushrod is that the gear had worked forward because the bolt holding on the cam gear threaded itself out a little causing the cam to be able to slide about a half inch toward the back of the motor,which caused the pushrods to bend i guess, so the new cam is in, all tightened up , lines up great and looks like no problems as of yet, top end is still apart

Now, if i get it all back together, what do I have to keep in mind when reassembling, how do I time the motor before i can start it up, firing order?

should I bring it to a mechanic to have these things done, how hard is it, my girlfriends father was generous to let me borrow a timing light, but im sure its much more difficult than just owning a timing light, any help would be appreciated, I worked so hard on this car, and have very very limited funds and would like to get her on the road very soon, thanks in advance and sorry for the long post.