A good start saves months of SEO work. Here is the basic technical checklist.
Indexing
A public site, a correct robots.txt, an up-to-date XML sitemap, canonical and hreflang for language versions.
Markup
Schema.org for the organisation, articles and products, plus correct H1–H6 headings.
Performance and mobile
Load speed, responsiveness, comfortable tap targets. Core Web Vitals in the green.
Localisation
Separate URLs per language, translated meta tags and hreflang, and x-default where possible.