Starting with SEO without result. Could you help

Just started with SEO. My company is visible on brandname on the first place, but I would love to rank on generic keywords. What did I do/what tools do I use - Google Search Console - Semrush (but switched today to Ahrefs). What do you recommend - All pages are with H-headlines - All pages have meta-description (using yoast seo) What can I do to start off. I made a page about a specific subject with potentially a lot of organic visitors, but without result. What can I do make a lot of pages to rank better. Or should I but backlinks? What can I do to see organic visitors, without hiring a agency. At the moment all visitors are from paid google ads search campaigns. Lastly, the website speed is good (use google speed tool to check this.) Also technical the website is healthy and I am using Https. Hopefully someone can help me out with articles, courses or videos. I do have basic knowledge about how crawling works and how Google ranks pages (content, autority and technical)