I have recently started doing weight lifting, not high intensity, I find I have really enjoyed it.

My question is when on my back doing the bicycle, I get charlie horses in upper shoulders or shoulder blades, how do I fight thru it to make progress in my workouts, doing the lower abs for me is very weak, and the muscles pinching and trying to relax them while doing the exercise is very painful.:

I've never had a charlie horse in my shoulders before, but I've had some really painful leg ones! You could try keeping your arms completely relaxed, don't pull on your head when doing bicycles. Another option for working the lower abs is to lie on your back with your arms relaxed on the ground beside you, legs straight up in the air and slowly lift your bum off the floor and back. Works very well!!

Try a magnesium citrate supplement a half hour before you do the workout. It helps your muscles relax a little and
you won't get the charlie horse. I used to get them all the time before I took magnesium daily.

Try to eat a banana every day.

A true charlie horse involves your lower extremities.A cramping in your upper shoulders or arm is most likely a muscle related strain from lifting.I would make sure you are using correct technique and if it continues...like doctors say, if it hurts, stop.