Keep it clean, structured content, long 1500+ words pages for home, about and service (depends on what you sell: services or products or just a blog).
Create social profiles on as many networks you want (post 3 times/ week) + other free backlinks, but quality ones and only manual work, do not use any software - backlinks in your niche.
Create ads on any platform that you want and run it for at least 2 weeks, with a small budget on awareness or reach with just 5 main [exact match] keywords for it. budget and number of networks depend on your budget, you just need to have search intent for that keywords and it will also gather data for future ads. Create the ads and do not let the paltform to automatically optimize it and you don't change the budget in the first 2 weeks - after that you should have all the data for scaling it.
Respect all the SEO recommendation for the site - do not use AI to build it (AI is usefull in creating a structure for the website, helping you to create the content), use any of the CMS platforms available - create webmaster account and tracking for google and bing. (do not overdo it with all the shit you find online about seo - just read google guides)
Hope you get the idea.
Good luck!