If you can't find the File or Help/About menu in TradeStation 10, it may be that your main menu has been disabled. If you look at the top left area of the TradeStation window, you should see the main menu as shown in the following image. That's the menu to use to open a new or existing workspace - which can be done in other ways using icons, but it's needed to get to Help/About so you can get your customer number, for example.
If that menu is not present then you can enable it by right-clicking on the background of a workspace. You must be on the background of the workspace, not on a chart - so if you have a chart showing, reduce its size enough so that you can click on the empty part of the workspace behind it.
When you right-click on the empty workspace background, the following popup menu will appear. Choose Platform Toolbars, and in the flyout that appears, make sure there's a checkmark in front of Menu Bar, as shown. Left-click to the left of the Menu Bar choice to make the checkbox appear. You should then see the File/Edit/View/Window/Help menu appear at the top of the TradeStation application.