^^ Rightly said.
Just get started with a smaller bike, 70 would be good to start. Once you're comfortable with basic riding control and road sense for riding then try riding couple of diff bikes 70, 100 or 125 in your friends circle, if possible. Riding different categories and brands will refine your control and will give you confidence.
Some tips; Always wear safety gear, at-least helmet every time you ride. Don't get scared of felling off, if you keep in mind in advance that you can fell from bike, then this will actually help you preventing from felling or worse you'll be able to make yourself safe in such situation. Don't try any stunts, racing etc.
Regarding sports bike, it will be very much different experience all together. Your previous riding exp will give you confidence in fast learning. You can ask questions about that from senior bikers, once you reach that stage!
Some guys directly start from bigger bike, you can do same but I'll not recommend that.
All the best and welcome to PW.