Also, don’t be afraid to look stuff up. And again. And again.
For HTML/CSS help, I would often google:
“w3 html TOPICNAME”, or
"w3 CSS TOPICNAME" - for example "w3 center text"
They have a great “Try it” functionality that lets you see the code and the result side-by-side, as well as change things and re-run the code to see what changes. This is how you really learn to code. There is no truer joke than this one about programming. I remember getting it as an undergrad on an email chain.
y = f(x)
return value = function (parameters)