I am a total beginner at using Inkscape and would like to ask a few questions.
Firstly could anyone guide me to a good set of tutorials on what each of the icons/settings do? or a set of tutorials for total beginners. Preferably videos but just text and diagrams would work as well. I found some through searches and even watched a few on youtube but they are mostly tutorials for when you are already familiar with inkscape.
For example I tried to experiment myself by first drawing an envelope, but I already ran into problems. Firstly it never snapped, so I enabled snap and experimented with the options I got d3 as a result, as you can see it visually looks wrong because it looks like there is a doubleline between the rectangle and the triangle. Next I tried using arrow keys to line it up and i got d1 and d2, finally I disabled snap and moved both shapes manually which gives d4, but as you can see there are problems with where the red boxes are, the corners are pointing out and I don't know how to get rid of them, resizing does not work, as then the rectangle would be the one pointing out. I'm sure it's probably really simple. I would like to know how to do these basic tasks such as snapping correctly, etc.

Thanks for your time and apologies if this is really simple stuff.