How to make proper html5 markup in Wordpress?

Question

HTML

through this service https://validator.w3.org shows the following structure of the page
Structural outline
[body element with no heading]
[nav element with no heading]
[nav element with no heading]
About Green Lift Complex Microfertilizer
Stimulates all biochemical processes
Compatible with plant protection products
Efficiency proven in more than 85 production experiments
Allows you to reduce the application rate of NPK by 10-15%
Why "Green Lift"?
Provides an increase in yield
Shows an adaptogenic effect
Stimulates and regulates
Satisfies increased requirements
Allows to reduce norms
Combined application
They talk about us
Reviews
Our products
Address
Contacts
How to remove the first 3 points? site https://green-lift.ru/

Answer 1

Changed the subject

Answer 2

to remove the first paragraph, add the page title in the h1 tag.
to remove the second and third paragraphs, you need to add a title (h2, for example) to the nav elements, or wrap them with another tag. as the spec says, not every link block needs to be wrapped in a nav.
anyway, here is more about it