Welcome to Starcraft 2 and welcome to the legions of the dayknights!
I would recommend for now that you just play against the ai and just have fun. Mess around, do silly things. Just playing at this point is going to help you learn to play far more than any video or forum will.
However, that being said, there are a few in-game options I highly recommend you change away from the default. Go to menu->options->gameplay
Turn off "simple command card"
Turn on "enable enemy unit selection"
Turn on "show game timer"
Turn on "display build grid"
Turn on "display hotkeys on command card"
set "show unit life bars" to either "always" or "damaged" (which is better is generally personal preference)
set "show flyer helper" to "always"
I also recommend setting graphics to low or medium, even if your computer can handle higher settings (higher settings clutter the screen and makes everything look more chaotic).
Also, when possible, use your keyboard rather than your mouse. This means instead of clicking on the "build scv" button, hit "s" on your keyboard.
If you still insist on watching videos, day has made plenty of them, so I'll link the most relevant ones:
(it's worth noting these are very old, and some information in them is obsolete. The core ideas are very good though)
So welcome to sc2, welcome to these forums, and good luck have fun. Feel free to ask more questions, there are plenty of lovely people here who will gladly help.