Chrome comes pre-installed on so many phones that lazy people probably just write "Chrome" rather than "web browser". It's nothing special, and any browser can do. You've probably got the Samsung browser by default.
As for the interface, a phone is not a PC, and things are optimised differently for a small screen navigated by fingers (relatively imprecise) rather than a large screen (space for many items) navigated by a mouse. So, no drop-down menus but if there's an icon consisting of 3 horizontal bars (probably in the top-left corner) that's a menu. Or 3 dots arranged one above another would take you to app settings or options for the specific view you are in. I don't use or know the Samsung browser, but a few guesses based on general experience of Android:
* no address bar: slightly surprising, but search and address are usually combined, so if there's a search entry field that will double as address bar. Some browsers also hide the address bar when you are viewing a page: if so scroll up to the top and it will appear.
* "close buttons" are unusual (take up a lot of space for niche function). This isn't windows, so you don't need to go around closing apps all of the time, it's better to just let the operating system manage your memory (uses less power than killing and reloading apps). For closing an individual browser tab, how it usually works is that in the top bar of the browser (see how to find address field above) there will be a little square with a number in it. That tells you what tab you are in. Touch it to get an overview of your tabs. You can close individual tabs from there, usually by swiping them away.
Some browsers use different ways of doing these things, so it does depend on what browser you are using. But those are fairly common interfaces.
If you really want to close the browser, choose the "multitasking" or "recent apps" view (one of the 3 navigation buttons on most devices, may be a long press on home button if yours is an older Samsung - Sammy make so many models I don't even try to keep track of most of them) then you should have a close button for each app, though swiping them away is simpler.