Cam degreeing is not an easy task to do first time around, and you don't need to completely understand it here and now. Confusing yes, just consider this your first step in understanding it and you can look into it some more at a later date.
You pretty much have it right now with your single keyway cam, the way you have it timed.
Like yellow rose says: Top Dead Center on #1 on compression stroke, then roll it over 180° and look at the lifter heights, if even then it is Straight Up Timed, just like you want. If one lifter is higher than the other then something is out of whack, advanced or retarded one way or another.
I just like to see first time engine builders use the single keyway timing gear and time it Straight Up just like factory, Not needing the degree wheel.
Using the multi-keyway timing gears and trying to advance your cam another 4° is where you want to start checking things with a degree wheel so it does not end up
way way off.
The degree wheel is a way to check everyone's machine work, making sure both keyways were cut into the right spots on the timing gears and dots in the right places, and that the cam keyways and lobe centers are where they should be for the application. Bringing it all together to give you the events that you want to see take place.
So yeah, you are doing good not to worry.
