I am not being sarcastic when I say that one of the first things to do is to use Search when you have a query, because the chances are high that your question has been asked before. This will save you a ton of time, because you can see the advice straight away, rather than having to create a post and then wait around for someone to answer. If you browse this section of the forum, you will find numerous threads where your current query has been asked and answered.
The next thing to do is the learn the engine. The best way to do that is to have a look at Andar's compilation of
info for new users. In particular you'll see a link to an interactive tutorial on the Event Command Menu. Not only can you learn this by playing (always much better than just reading or trying to watch a video) you can also open it up in your editor and
see how everything was done. There is also a link to a playable tutorial on Switches and Variables. Get those 2 under your belt and you will have a very solid foundation for making a game. Without them, you face a life of grief and frustration.