Do I need to submit a sitemap using the SEO plugin?

Sorry for my ignorance, but I've never gotten serious about SEO before. However there's a lot of interest in articles I'm writing about vitamin C and skincare so I decided to go for it.

I installed Infinite SEO and am busy filling in the blanks. However it seems to assume that an XML sitemap will be submitted and I don't have a clue.

Do I need to submit such? Will you please point me to a tutorial of some sort?

thank you!