I have the same camera!
Hopefully, you got the body with a kit lens. It should work fine for all those things. Although, my satisfaction is declining with it everyday. I also have the 75-300mm f/4.5-5.6. I have yet to try with this lens for sports, but the kit lens works fine with bowling.
For landscapes, you could use a wide angle lens. I'm thinking about a 28mm f/2.8. For sports, Sony (and other companies) have more options. There is a quite expensive option, but it has a very nice range and a very goo f number. It's the Sony G70-200mm f/2.8. $2000 if you have the money.......
A couple of members know more about Sony on the forums than I do, HappyHour, eravedesigns, and shorty6049. Ask them.