Changing Guitar Strings Les Paul

will changing the strings fix my guitar?
its a epiphone les paul. i havent played it in over a year, because i got a new guitar and was playing that one, i went to play the les paul and it was extremly outta tune. i pluged the tuner into it and its so outta tune i think that the tuner is tunning it to the wrong strings, like when i hit the low E (6th string) it thinks it a G (3rd string) and its making it more outta tune. i know the tunner is fine since it works on the other guitar, is my les paul now so severly outta tune ill never be able to re tune it right. so i guess im asking, if i put new strings in it, should the sound improve enough the tunner will be able to show me how to tune it.
Change the strings…making sure you have at least 2 1/2 to 3 string wraps around each tree. Make sure the screws in each tuning key are still firm.
Stretch your strings at the 12th fret. I don’t mean string bends, but grab the string and give it some gentle, but forceful pulls..sideways, up and down and away from the body of the guitar.
Use your other guitar as a basic tuning reference point to get your new strings “in the ball park.” Then tune your new strings with the tuner.
After it’s close…play harmonics at the 12th fret (lightly touching the string without pressing down) and fine-tune.
Best of luck.
How to Change Strings on an Electric Guitar : How to Use a Les Paul-Style Guitar Headstock