You will first want to download and install the Hiro Wallet which can be installed on Google Chrome, Brave, or Firefox browser.
This tutorial will show you how to do it through the Brave Browser.
Firefox link:
https://addons.mozilla.org/en-US/firefox/addon/hiro-wallet/
Google Chrome and Brave link:
https://chrome.google.com/webstore/detail/hiro-wallet/ldinpeekobnhjjdofggfgjlcehhmanlj
Once installed, you should automatically be brought to a similar page.
Click "I'm new to Stacks" button
Save your Secret key and put it in a place where you won't lose it. If you do lose it, you lose your account.
Click "I've saved it" button
Enter a strong and unique password and then click "Done"