I'm a programmer. What can I do with Cardano?

I’m a Java Programmer. I like to get my hands on Cardano Programming. But I have no clue where to start and what I can do with it. I know there is the wallet Daedalus. But other then that? What can i do with it. Can i write some code like a Hello World example or anything? Where do I start. Can I develop a credit card app and pay with ADA. Can I buy coffee with ADA?


Sell? I cant believe it has been more than a year and no LeDgEr

There’s some good resources in this thread for starting out with smart contracts:


Thank you I will look into it.