For beginners it’s worth checking out the most popular guide written by some of the industry experts. They can be a bit generic but will give you a good understanding of the different disciplines and show you how to increase your sites rankings in a safe and natural way thats within google’s guidelines
This guide is great for learning about on page SEO and how subtle onsite changes can make a world of difference, when it comes to on page seo being a stickler for the details pays off.
Backlinko has some fantastic resources, while the site originated with the aim of specifically helping people link build they’ve also developed a list of the top 200 factors that will improve your ranking
My Own Personal Advice
When you are learning SEO the hardest part for me anyway was staying head strong and trusting my changes, it can takes days, weeks and months in some cases to see an impact for the changes.
For example it could take 3 weeks for titles and descriptions to have an impact, it could take a month or even more for a blog to see any impact and it could be 5+ months to see an impact from links
The second hardest thing, is knowing what articles to trust online. Start with the resources I’ve given you above and sign up to my newsletter for my next article on what communities to follow
If there’s any advice I could give anyone trying to learn SEO it would be to start their own blog or website, the skills you will pick up will be invaluable.