What has allowed me to learn at my best pace, and still does, is building a small practical application with my knowledge, or solving challenging problems. Finishing something you made, which is also useful, is motivating to continue and create more things. Not knowing enough is a minor problem which is often aggravated. You can usually find resources to learn along the way of a small project.
What exercises do I recommend? You have to look around and think of small doable hacks achievable with modest programming knowledge. Things that come to mind —
1) Is there something monotonous you do every day? Can it be automated with programming?
2) Does your computer have lots of disorganised stuff? It would be fun to arrange and analysing them.
3) Do you come across a data format that's hard to read and parse? Can it be converted into something easier like CSV?
4) Is there something that you need to check manually often? Can it be achieved by some rudimentary scraping and alerts?
5) Are there any public data sources that interest you? Do you think you can analyse them using programming?
Apart from this, I used to be driven to solve Project Euler [1] problems which get invigorating and challenging after you're done with the easier ones.
My experience suggests that people develop their own ways of learning something; not everyone's playbook is same. But the general observation is that it's when they have fun, they learn the most. Try and experiment with what you enjoy most doing, and develop a habit of doing more of it. Good Luck!