According to SEO
A website contains two parts for marketing where the optimization needs to be done. These are on-page and off-page. You have to ensure with your service provider that all the required optimization parameters are full filled in the website. These must include all the services that come in your package. Some of the things that must be included are Meta tags, sitemap, keyword density, relevant content with appropriate keyword density, anchor text, alt tags in images, proper link map structure, etc. All these points work towards increasing the organic search traffic towards your website.
On-page optimization is very important these days, there is no doubt to it, if you want to do on-page optimization then you have to learn it deeply for better result, I would say, no doubt to it.