I just created a second gmail account.

Every program you use has a tools menu. If you use tools a lot it will be a toolbar across the top of the screen. If you rarely use tools it might be hidden. In Windows you can click "Start" and select "Control Panel" and that gives you a menu of menus to control everything the computer does. You can right click anything and most of the time get a menu for that specific item. For example if you right click the desktop you have the option to rotate the monitor image in some graphic cards. That allows you to have an image that is high instead of wide, by turning your monitor. You don't need to memorize all these things, just be aware that they are in there. Then you can claim to know how to operate a computer at the beginner level.

At some point you will learn about cookies. Your browser has an option to inspect and delete cookies, but there are a lot of cookies that your browser does not know about, so you need to get a cookie manager. When you log into any site, the site sets a cookie on your computer. Any time you post a message, the site looks at your cookie to see that you are already logged in. When you come back for another visit, the site sees that you are already logged in, so you can't log in as someone else unless you first log out of your old identity.

This is all basic stuff that you need to know when you use the internet, and everybody you talk to assumes that you know it perfectly. You should occasionally visit www.howtogeek.com/ or some such site to see if there is anything new that you need to learn.