Session 1: Covers GitHub+GitHub Pages, creating and linking files and folders, centering in CSS, CSS positioning, and creating a responsive image gallery using flex.
Session 2: Covers the same as above, but focuses on a "splash page" instead of a responsive gallery.
If you're having a hard time getting your final project started and need a refresher on the basics, I suggest watching/doing the following tutorials. You can complete all this stuff in about 6-8 hours.
Watch videos 1-22 of this playlist. These start from the very beginning, and start introducing more advanced concepts around halfway through the series. I recommend watching other videos on that channel for more specific CSS techniques!
Do these HTML and CSS tutorials on freecodecamp.org
28 HTML mini tutorials
55 CSS mini tutorials
44 (optional but useful) CSS mini tutorials
Don't worry about writing your code in VS Code at first if you'd prefer to work in Codepen. I recommend creating a single pen for each web page you plan on including in your website. You can copy and paste it into VS Code later.