I'm posting this answer to give insights into multiple ways available for you to change the project on GCP. I will also explain when to use each of the following options.
Option 1: Cloud CLI - Set Project Property on Cloud SDK on CLI
Use this option, if you want to run all Cloud CLI commands on a specific project.
gcloud config set project <Project-ID>
With this, the selected project on Cloud CLI
will change, and the currently selected project is highlighted in yellow.

Option 2: Cloud CLI - Set Project ID flag with most Commands
Use this command if you want to execute commands on multiple projects. Eg: create clusters in one project, and use the same configs to create on another project. Use the following flag for each command.
--project <Project-ID>
Option 3: Cloud CLI - Initialize the Configurations in CLI
This option can be used if you need separate configurations for different projects/accounts. With this, you can easily switch between configurations by using the activate
command. Eg: gcloud config configurations activate <congif-name>
.
gcloud init
Option 4: Open new Cloud Shell with your preferred project
This is preferred if you don't like to work with CLI commands. Press the PLUS +
button for a new tab.

Next, select your preferred project.
