1st Time Engine Rebuild.... Installing Distributor

I took my old distributor out of the engine I pulled and am switching it over to the rebuilt slant 6 engine. The engine is currently out of the car and on a stand. Using layman's language could someone help me walk through the steps of getting this installed correctly.... I've read a bit online here already, but sort of need to internalize and confirm my understanding of what matters. I'll also tell you what I don't know.

Step 1: Try to get the engine to tdc. I've already got the head on so I can't see the pistons. I already have the timing chain cover and harmonic balancer. Some suggested using a wire through spark plug #1 and feeling for tdc as I crank it over by hand...... yes?

Step 2: Once i've got tdc... i'm wondering what matters next. I truly don't understand the whole importance and method of the distributor install. Do I just put it in position and make sure the gears are meshed? Do I have to take off the cap and look at something and line it up? This next step is confusing to me and I'm not really sure what matters.... please help clarify this a bit.