about oly 45/1.8mm ane PL 25/1.4mm

Get a zoom. Play with the zoom. Discover what focal lengths you like to use when composing your pictures. After doing that you will figure out what primes you want.

Luckily, you probably got the 12-50 with your E-M5. Great! You have a wide angle all the way to a telephoto. You can mess around with it until you figure out what focal length best suits the pictures you take, then you can decide whether or not any of the primes would be worth the expense.

Or you could just spend hundreds of dollars on primes -- you can do that, too, I suppose, if you've got the cash.