Some clarity on YouTube tutorials used in my projects

I have a bit of a question in general. Is it fine to use YouTube tutorials online to get a general sense of how to structure a project, as long as its linked to the original video used? I would like to know if its fine to use said videos to supplement my CSS and give me a better understanding of HTML layout in my certification projects. Is this acceptable? (I’ve already accepted the plagiarism policy).

if you already have a design created (either by hand drawing it or through some mock-up) and you already made an attempt to code it then speaking for myself, I don’t see an issue with you looking up solutions to coding issues you have online (whether on youtube or elsewhere).
I strongly encourage you to do the design and writing of the code first before looking at other people’s code. Using other people’s code only to help you solve specific problems.