There are certain key aspects to consider if you want to implement an SEO strategy at an international level:
Analysis of the markets and the target audience.
Study of competition in each market (benchmarking).
Study of specific keywords for each market.
Decide the architecture of your website: domains, subdomains and subdirectories
Choice of hosting.
Localize the content to adapt it to the language and country of your target audience.
Correct implementation of the hreflang attribute.
Implementation of a geolocalized link building strategy.