Best way to learn HTML & CSS

As others have mentioned, Youtube and W3Schools are some great ways to learn. I'd also recommend taking a look at sites like Neocities of which are great ways to test out your website while keeping tabs on what you've updated. It can be a hassle to learn CSS but it's relatively easy to get into compared to C++ and Python. Oh, also look around at other websites and keep note of what techniques they utilize.