https://www.creationkit.com/index.php?title=Category:Getting_Started

This will get you up and running with the creation kit. Bear in mind this covers how to get/install for both "oldrim" and special edition, so be sure you're following the right portion of the guide for your version of the game.

Once you're set up, there is a tutorial hub link on the page, with more common tutorials, and there are a ton more that you can find with the search box and a keyword or two.

If you prefer videos, there are many but I find Darkfox127 on youtube makes a good and easy-to-follow series. I encourage you to combine the two, read a tutorial on a task you want to complete, watch a video to see how it looks as it's being done, and then keep the text tutorial open to refer back to, if you get stuck.

There is also a lot of information available via UESP.

https://en.uesp.net/wiki/Skyrim_Mod:Creation_Kit

https://en.uesp.net/wiki/Skyrim_Mod:Creation_Kit_Usage

Also there are many searchable forum posts available on nexusmods.com, afkmods.com, and here on steam. Sometimes helpful to see what others have gone through, to get a job done.

My tips to you: Save constantly. When you get a stable something, save it and copy it. Put the copy away in a labeled folder. If something goes very wrong, you break out the latest working copy, make another copy, and start from there. For your first few mods, don't be afraid to trash the whole mess and start over.

Thanks