So I have a Shimano derailleur and it shifts up decent only problem is it does not shift to the gear it's supposed to shift to. On my bars it will say I'm in gear 5 for example but the back of my bike is on gear 6. It is like that with every gear so 3 on my bars is gear 4 on the back of my bike. And 1 on my bars is 2 on the gears of my bike. It's kinda annoying I played around with the tension on my derailleur and the limit screw a bit that did not help any. If anyone has any suggestions on how to help they would be greatly appreciated.
This sounds like the classic case of inner cable tension is wrong. If you can see bare wire down beside the downtube, try tugging that with your hand and see the rear derailleur move.
Set the shifter to what should be the "easiest/slowest" gear, which is probably the highest number. Then with the rear wheel off the ground, hald-pedal your cranks and pull the visible wire till the chain is on the biggest rear cog. That is the amount of slack you need to remove from the wire.
Do this at the rear mech, for an initial coarse setting. Then as you get closer look at using the barrel adjuster to dial it in better.
Don't fiddle with the limit screws - they generally don't need changing unless you're swapping parts. If you have changed them, change them back. Otherwise you run the risk of the chain jumping "over the top" and making a surprising amount of damage.
This sounds horribly complex, it isn't. However its hard to describe in words, so it can be easier to ask for assistance in person from someone locally. Does your location have a Bike Cooperative ?