What are the exactly steps need to do to meet a project requirements of aprache2 licnese?

Question

When we find a web app on GitHub with apache2 license, we would like to host it for the public to visit.

From https://tldrlegal.com/license/apache-license-2.0-(apache-2.0)

Must part.

1. Include Copyright (Describes whether the original copyright must be retained.)
2. Include License (Including the full text of license in modified software.)
3. List item State Changes (Stating significant changes made to software.)
4. Include Notice (If the library has a "NOTICE" file with attribution notes, you must include that NOTICE when you distribute. You may append to this NOTICE file.)

What are the exactly steps need to do to meet the apache2 license requirement?

When we build the web app locally, the fond end doesn't have any licenses and copyright information.

1. For 1. Where do we put the Include Copyright information?
2. For 2. Where to put our License (if we decide to use one to work well with apache2)
3. For 3. Will improve the UI, and database. (Where do we state the changes?)
4. For 4. Where to put our notice? (Do we also need to put our code on GitHub?)

Please use layman term if possible. (an ESL here).