Barre chords are usually hard in the beginning, so give your muscles a chance to work up to the task.

Using a pick up on your acoustic, with an amp will not make barre chords any easier but you'll be louder. Electric guitars are generally easier to finger as the strings are lighter and the neck more narrow but acoustic is a great place to begin.

There is no good or bad time to start playing electric verses acoustic, in my opinion.

If, after practice, you still have trouble fingering barre chords on the acoustic, using lighter gauge strings can make it easier.