Hello
first you will need to install the plugin named as contact form 7
go to dashboard >> plugins >> add new >> search for contact form 7 >> install and activate it

now go to dashboard >> contact >> Add new >> and set up your contact form

it will generate a contact form shortcode copy it

after this you will need to add a contact form page
go to dashboard >> pages >> add new >> set title as contact >> set template as contact page from the page attributes on the right side panel >> click on publish

now go to dashboard >> appearance >> customize >> contact page >> scroll down to find the shortcode text box >> paste the contact form 7 shortcode in it which you copied while creating it >> click on publish to save the changes

dont forget to add the contact page on the primary menu otherwise it wont appear on the front page menu

Thank you