HTML & CSS

I am beginning to understand the basics of HTML but there are a lot of codes that I would constantly have to go back to to remember. The style sheets I think will be a lot more difficult to use. The You Tube videos did clarify some info on HTML but were done on a windows base computer and I am a Mac person so I don't know how that will transfer for me. I am sure it will all come together as I begin to try things out.