Hope your dad is doing ok!
If you have a story, perhaps consider drawing something with your characters in it to keep your interest, like maybe if ur character is traveling somewhere, and u draw the bg for that with them in it (thats what i do at least haha)
Oh clipping is quite simple and i use it all the time: say you have a circle on the bottom layer. then you make a new layer above that, when you draw without clipping, it goes all over the page. BUT if clipping is turned on, it only colors the circle (or whatever shape or line/stroke you are clipping to) therefore helping u color within the confines of that shape
Personally i dont recommend using multiply layers until you get a good grasp of shading - using it randomly makes the colors look weird - personally i don't use it often - i just color pick the colors i want
I'll make a video of a study for you tomorrow (I hope lol - will email myself so that i don't forget.)
BTW i do recommend that if you are trying to color/shade in grayscale that you also turn the pic grayscale like it is for the second pic that helps in differentiating the different types of grey to use.
such a good idea i always plan for too many things and never get all of em done XD
btw your building/persp studies look great i think!
you also did really good on the one you drew traditionally and i think its just in the digital ones your colors are too far apart in terms of value. if you picked closer shades of grey it'd look better too.
^ I LOVE these tiny people they are SO cute XD