Hi there! Sorry about this really late reply. I don’t know of any tutorials for Open Canvas, but maybe searching on deviantart for “Open Canvas Tutorial” will help you. As for software alternatives:
I personally use Clip Studio Paint Ex, which is only around $5 a month for 7 months, then you get to use the software for free for the rest of your life. It’s in japanese, but there is a translation team on the forums of sai.detstwo.com that have a complete translation of the software in case you can’t understand japanese. The program is pretty straightforward though, and you’d be able to figure it out anyway. It’s a very powerful program.
There is also Paint Tool Sai which cost around 30$ or so, but I’m not entirely sure. It’s a favorite among some digital artists.
Other alternatives include the GIMP, which is free and has actually updated to include many of the tools that photoshop does.