Relationship between a Lander and the Hompage of a lead gen site


Hello - Guys - I am very new to Unbounce : )

I will be using ppc to drive traffic to my site.
Iam grappling a bit with the concept between a homepage and a lander…

I know that we should be using a landing page when traffic arrive via ppc.

Do we have both or do we have a link from our lander back to our homepage - for example when someone needs to establish a bit of trust before they fill in the form - but then they would have navigated away from the lander?

Currently we only have a lander and then some links at the bottom for privacy policy and about us etc

So were thinking of building the site out with a homepage as well - but hence my question above.

So do you guys use Unbounce then for your entire website ?

Or is there a URL someone can share from a site using a unbounce page as lander while the rest of the site like the homepage is in php. I just need to see how the navigation / flow works ?

Would be really cool if someone can give us some pointers on how to approach this.