I adopted two kittens -- a brother and sister -- 10 years ago. Once you're sure you're really ready for all the responsibility that goes along with having a cat (regular vet visits, shots, proper food and care etc. and all the money and time and commitment those things require), adopting is a wonderful thing.
You can go to your local shelter and meet some kitties. You will have to pay for the vet bills that the shelter has already incurred -- shots and neutering or spaying -- before you can take your chosen kitty home with you.
I lost one of my cats when she was 3, but her brother, Hank, is still with me. I love him SO much. Good luck!
P.S. You may think you want a tabby now, but you never know which cat you're going to fall in love with at the shelter. I THOUGHT I wanted a long-haired grey kitty (like the one I had when I was a kid), but Hank chose me... He walked right up to me, with his funny, bow-legged swagger, and started yowling at me. I wasn't looking for a white and orange short-haired cat, but he was looking for me... It was love at first sight and I decided to bring his sister home with us too.