I'd probably keep one familiar Pokemon, if I were you. That way, if your in any trouble, you know what moves and strategies you can use, without any hassle.
I've had the same problem before MANY times. I always end up with the same boring old team. So, to fix this, I thought outside the box and caught Pokemon who I just wouldn't go for. Sure, I'd probably drool at the first sight of an old Pidgey but, I'd kick it's ass and get a Spearow instead.
If your unsure of your Pokemon, check on websites that state their movesets and abilites, etc, and find out if you think it's a good Pokemon. Try the Pokemon out, if it don't work, start the game again. I've been doing this SO many times but, i know I've got a good team now.
Oh, and you could try releasing your Starter Pokemon. Might seem difficult but, sometimes it makes the game a whole lot more fun.
I hope I helped in some way! Thanks for reading! ^_^
