If I add X to 5x would it equal 5x^2 or something else?

NO !!!!
5x + x = 6x By Addition
5x^2 means 5x X x By Multiplication.

If you ADD x to 5x you get 6x

Let x be 10 apples. this is how your question translates to:

If I add 10 to 5 times 10 would it equal 5 times 10*10 or something else?
If I add 10 to 50  would it equal 5 times 100 or something else?

Is 60 equal to 500 ?


Now try with x=1 or x=2 etc.

Conclusion?

If you add x to 5x it equals 6x.