I agree with you, 6 ft is a good starting point. The arrow at full draw needs to be parallel with the ground (level).
Adjust the string as low as you want to start. Set the nocking point so the arrows do not tear the paper up (NP too high), or tear down (low N.P). Then twist the string after a few shots about 5 turns (1/4") and retest. Find the sweet spot. For a RH person, arrow to the right is weak, to the left is stiff.
For paper, I use a 24" wide roll of brown painters paper from a paint, hardware or home improvement center. Build frame from 1" dia. PVC pipe and unions, and T's that looks like a football goal post with feet. At the top, use a T on each post, and run a 1/2" PVC pipe thru the roll and holes in the T's. The paper roll should be above your head, so you can pull the paper down, to a cross arm, and use a clamp to hold the paper tight. If you don't cement it together, you will be able to tear it down for storage. Good luck.