Bike Reviews

I found a shock absorber from a mountain bike one day and tried to put it on my mountain bike with a plain fork. It didn’t fit because the bar on the shock absorber was too thick to go through the hole in the frame of my mountain bike. Is it like this with all bikes without shock absorbers?

So i got a full spension mountain bike and i need to add air to the rear shock. But the stem on the rear shock is too short. When i use my air compressor to add air, the nozzle of the air compressor wont fully connect to the stem on the shock because the body of the shock is in the way. its hard to explain, but long story short, i think i need a stem extension or something like that. do they make those? anyone got a better idea?
thanks