You have to create sub-folder in main domain - As said above. If you created different websites (domain name) for different regions then it's so much hard to optimize that all websites. If you created website with different regions as a different sub folder in main domain then it's an easy for optimizing your website for local regions.

To optimize your website locally, you have to use local SEO strategy for more traffic and leads.

Complete your website with all necessary on page SEO parameter e.g. as you said meta title, meta description, meta keywords, use of H1 to H6 tags and lots more.

You must have to keep unique and quality content on your website. Finally, submit your website to all major search engines and wait for the crawl.

If your domain name is unique (not a common name) then it ranks at top position within a short period of time....

Where you are struggling with your code? At least share some piece of code where you have problem for a better solution.