If you don't have it, get a UV filter. The last thing you want is a scratch on that lens. Make you get a good one, like a Hoya ($25 - $30). Lousy to ruin the optics on your camera with a lousy filter. I got the Lowepro Slingshot AW100. Should have got the 200. Nice little bag, but it's already full, with the flash and the charger. If I got another lens, light diffusers etc., I'd need a new bag.
Good plan to take your time. Shoot a few thousand shots with your camera (I think I have > 3000 now in 9 months) and see what you like and don't like and can and cannot do, then make your decision on things like flashes and lenses, etc. Saves buying the wrong thing.