The distance betweeen the 1st fret and the string and 12th fret and the string seems to be different on my guitar.(much greater at the 12th fret)
Would this be bowed, twisted or warped neck or is it normal?
Someone told me I should get it looked at.
What do you think?

Perfectly normal, but may need a setup. You can lower the bridge/saddles to reduce height at the 12th fret. You can also tighten the truss rod to lower the action. However, which you should lower (the bridge, tighten truss, or both) is dependent on the action across the fretboard and where buzzing occurs when lowered too far. You should consider getting your guitar setup professionally if you think it isn't right.