There are a lot of good tutorial resources out there, some of them free, but for the most part if you want a high quality video tutorial, you'll need to pay. Well, this is a rare exception.
Lonely Speck is a couple, Ian Norman and Diana Southern, who are experts in astrophotography. Their YouTube channel is one of my favorites on the platform and they create some of the best starscapes and Milky Way images out there.
In 2016, they created a full astrophotography workshop which covers everything from the technical, theoretical information, through to post-processing once you've got your shot. They have now uploaded the entire thing to YouTube, which you can watch for free. It might be the best resource for astrophotography that any beginner could hope for.
Though I haven't got to do as much astrophotography as I'd like due to where I live, I have done it whenever I've had the chance. There is one thing I learned very quickly indeed: post-processing is everything. There are few genres of photography — if any — that require more nuanced work in post to coax out the best possible image. As a result, astro can be off putting for beginners. Well, make yourself a drink, grab a notepad, and receive a free masterclass.