Summarize the following:
It's in the bottom-right corner of the screen. A pop-up menu will appear. You'll see this in the pop-up menu. It's near the bottom of the menu. You may be taken directly to the Photos page on Android. Tap the album or folder in which the file that you want to upload is located. Tap a photo, video, or document to select it. If you want to select more than one file, tap each file that you want to select. It's in the top-right corner of the screen. This will prompt your selected file(s) to begin uploading to Google Drive. This can take several minutes to several hours depending on the file size and your Internet connection. Once the file completes uploading, the file's progress bar will disappear. It's important to stay near a Wi-Fi router and keep Google Drive open during this time.

Summary:
Tap ＋. Tap Upload. Tap Photos and Videos. Select a location. Select a file. Tap UPLOAD. Wait for the file(s) to finish uploading.