1. It'd be nice to have movesets when evaluating your team. It's difficult to know what you're really capable of in battle if no one knows what moves you can do.
2. A lot of people here actually go to tournaments with their teams to compete. So if you're not using level 100 Pokemon, it's highly likely that they could beat you.
3. This is just off the top of my head, but I think you have a 3x weakness against Electric attacks. (Krabby, Pidgey, and Shellder are all weak against Electric.) 3x weaknesses are usually very detrimental. Start by making a team that has no more than two Pokemon weak against any given type of attack (since that's really as good as you can possibly get), and work from there.
Oh, and if you really want to battle people, try the Online Pokemon Battling forum. That's a good place to actually test out your team.