To make yourself less shy will take some time and practice. Take baby steps. Then over time you can expand more. The first baby steps I would suggest is to start greeting people with hello's and goodbye's.
Here are a few examples:
1. How is
your day going?
2. How was
3. How was
4. Good morning John.
5. Good afternoon Lisa
6. Hi Barbara. How are you today?
7. Have a good day Bill
8. See you tomorrow Janet
9. Good night Julie.
10. I hope you're having a good day.
11. What you got planned this weekend?
12. What you doing this weekend?
13. What you got planned for tonight?
14. I like those shoes.
15. I like your new hairstyle.
Basic hello's and goodbye's is a way for you to build up your confidence when it comes to talking to people. There are no expectations or pressures of having long conversations. These are brief interactions. Try to practice this in your every day life. It could be the cashier at the grocery store. The cashier at the fast food restaurant. The clothing store at the mall. Your server at a restaurant. This is how you create small talk.