Your playing itself isn’t that bad, but it’s noticeable in the first videos how hard you’re hitting the strings. You do need to work on unwanted noise, but it’s not too excessive, however some effects can really amplify any unwanted noise. Justin does cover this in a lesson, but I’d say don’t get too hung up it for now, just concentrate on progressing through the lessons.
As has been mentioned, moving from acoustic to electric, you need to learn to not hit the string as hard. There are some songs, where the added harshness of really hitting the strings hard adds to the dynamics, but a key skill of electric is knowing how to use those different dynamics.
The other key skill is learning how to use the guitar itself, and the amp to get different tones.
I’d suggest spending some time with the amp set fairly clean, and experimenting with just the guitar controls, and how you hit/attack the strings.
Then once you have a consistent basic tone, try experimenting with the amp.
I know you bought a single coil Strat, but this video highlights the range of tones that can be achieved solely with a guitar -
(10) Joe Bonamassa’s Gibson Les Paul tone tips guitar lesson - YouTube
The same applies to single coils, it’s just you won’t get the ‘fuller’ sounding tones.