Hold down the power button for 10-15 seconds to force shut it down. Wait a few seconds and tap the power button again to turn it back on again like normal.
When a keyboard becomes detached from the screen on a Microsoft Surface, it often goes into Tablet Mode, which makes the desktop disappear and the start menu take up the whole screen and should go back to desktop mode when reattached. Sometimes you can accidentally put the Surface into Tablet Mode if the keyboard becomes slightly detached from the screen without realizing it.
To put the Surface back into desktop mode, first either click/tap on the notification bubble in the bottom right of the screen (1) or swipe from the right edge of the screen (2). Then click/tap the Tablet mode button to turn Tablet mode off (should be greyed out if off.)
First make sure the Bookmarks bar is showing in Chrome by clicking the three dots in the top right. Next go to Bookmarks and make sure "Show Bookmarks bar" is clicked.
Then on the desired website, click on the URL to highlight and then drag down to bookmark.
You can also create folders to organize the bookmarks. Right click on the bookmark bar to create folder and then drag in bookmarks to the folder.