Wow, now this does sound like quite an interesting and fun topic to look upon when it comes to basic html/css programming, first thing I would reccomend doing when trying to take up learning something such as this is to make sure you have some actual experience with anything that's based around technology or the internet, I would basically begin by using a simple site such as Codecademy, which of course, people have already mentioned numerous amounts of times or if you ever wish to grab some informative facts about the history of html/css then just take a quick look at what wikipedia has to offer. As for the thing about being un-patience around learning new things, just don't let that get in your way, we all have a long life ahead of us, we have time. Besides, at the end of the day, what fun would it be if you were to rush things? It took us years to learn how to talk properly, this would be quicker. Oh and here we go with the very un-relevant points I am choosing to make.
Just take it as some sort of life thing, take a look at it sometimes, if you get bored, feel free to step away from it for a while and whenever you feel the need to take on that one thing again, do some more research!
Like I always say, it only matters if it's some sort of exam work. If it's only for your own accord then, okay.
Have fun learning! (Also, please do not take it as a way of trying to sound very...this is only from my point of view and was never intended to sound threatening or offending. Thank you..)