These are two building blocks that I created using tinkercad, with a photo of a real lego block to guide me.
I spent about 3 days working on these making sure everything was symmetrical and they could fit together with one another*.
*I don't know about their compatibility with real Legos but I'm confident that you could print out as many of these as you want and build away!
Step 1: Then I Uploaded Them to Thingiverse
These are the links to go to so you can download and print your own LEGO inspired building blocks: