Try to hit every official Yoyo 2.3+ tutorials before going out in the Youtube tutorials wilderness. You'll me much better off starting with stuff you KNOW works 100% and is "endorsed" officially. You can download and access them directly from GameMaker itself, it's pretty cool. Scratch that last part, as per the post below, which I was not aware of!
Just seen this in todays Release Notes, so scratch my previous comment about using the in-IDE (ie. Start Page) tutorials and follow this advice instead:
https://www.yoyogames.com/en/tutorials is our newly-updated and expanded website dedicated to tutorials and other learning resources, which allows filtering by proficiency level and also by the topics you're interested in
Please note that we do not recommend continuing to use our old Start Page/Marketplace tutorials in 2.3.2+ IDEs, as these will have formatting issues and some problems with links to videos - these old assets will be removed from the Marketplace in future