If you want to install a package from Salesforce Appexchange you can follow the below steps

1. Go to the Salesforce AppExchange website (https://appexchange.salesforce.com/).
2. Search for the package you want to install. You can search by keyword, category, or vendor.
3. Once you have found the package you want to install, click on the “Get It Now” button.
4. Review the package details and click the “Continue” button.
5. Select the Salesforce organization where you want to install the package and click the “Install” button.
6. Review the package terms and conditions and click the “Install” button.
7. You will be prompted to log in to your Salesforce organization. Use your Salesforce credentials for login
8. Review the package permissions and click the “Continue” button.
9. Click the “Install” button to start the installation process.
10. Sometimes installation takes time so wait for it to complete
11. Once the installation is complete, you will see a message indicating that the package has been installed successfully.

Then you can navigate to the installed package and start using it.

It’s important to note that some packages may require additional configuration steps after installation, so be sure to review the package documentation for any additional instructions.