Step 1: Open Recent Projects :
Firstly, open the Android Studio. You will see Welcome to Android Studio on your computer screen. After that we could open an existing android studio project in Android Studio from “Recent Projects” directly. Just click the file name in recent projects which you want to open.

Step 2: Open Android Studio. After that you Click on “Open an existing Android Studio project”.

After that Select the File location where your file is located. We located and selected “HelloMindSpark” project and then Click OK.

Step 3: After that click on Projects >> app and then Click java and choose “MainActivity” file. Here your java file for coding Android programming will be opened.

Step 4: After that Click res and then click layout and choose activity_main.xml file. Here your xml file for designing Android UI will be opened.
Open XML

How to Open a project when project is Already Open in Android Studio
Step 1: Click on File and then Click on Open.
Open
