Web Browsers
Firefox and Chrome (or its Linux version Chromium) are two familiar web browsers that are installed. Click on the icons of these web browsers in the panel at the bottom of the screen towards the left to open them or from Menu --> Internet. There are other browsers you can install yourself and try out.
Which of these is better? It's mostly a matter of personal preference, but speed may be a consideration on older computers. Very generally speaking, people with privacy concerns might prefer Firefox, and users who use Google apps a lot might find Chrome more compatible. Try and see, and decide from your own experience. Read up.
Firefox
The Firefox offered here is set up for those interested in privacy on the web. The Startpage search engine is set as default. Startpage is a search engine that, unlike Google and others, does not track you. Ublock Origin, a plugin that blocks advertisements, has also been installed for you.
Blocking ads on the web is a controversial issue. Sites use ads as a source of income. However, some ads are obnoxious and some are even malicious. Some can pose a danger to children. For these older computers, many ads, or too many ads cause problems loading pages or even crashes. In fairness to sites that use ads legitimately as a source of income, you can disable this blocking on a page by page basis.
Chrome or Chromium
Chrome is the browser that, at the moment, about two thirds of the world is using. Chromium is its opensource version. Chrome is known as being fast, but a little resource heavy. When a company has two thirds of the world's users it can call some shots. To be fair, Google, Chrome's creator, has used its clout in various ways to make the internet more secure, and has even gone as far as getting rid of certain kinds of obnoxious ads, and has plans to cut down on tracking. Keep in mind, however, Google is essentially an advertising company, its income coming from collecting vast amounts of information from those using its services. If you have serious privacy concerns Firefox may be a better choice. You could also try Chromium, which is open source. On the other hand, Chrome, since it is Google's creation, is likely most compatible with Google's various services if you use them a lot. Also, since two thirds of the world uses Chrome, it's a safe bet websites will work well.
Both Firefox and Chrome have numerous add-ons available that add all sorts of functionality. It can be hard to resist the temptation to go overboard installing these but it is suggested you go easy. Each add-on requires a little more memory to run, and too many will definitely slow down and strain these older laptops.
And much more...
If you ever become adventurous or just curious as to what is out there, there are lots of possibilities to explore. Opera, Vivaldi, and Brave are all cross-platform browsers with dedicated followings, each with its own unique appeal. And there are more.... Be an informed web surfer. Check them out.
Tips for older computers
Tabs It is easy to end up with many open tabs or windows in your browser. Don't! Keep an eye on the number of open tabs and windows. Be aware clicking on something may open a new tab. Everything will be faster and smoother if only one tab is open in one window.
Add-ons When you become aware of the number of awesome add-ons and plug-ins that are available you may be tempted to install too many. No matter how awesome, add-ons use memory and system resources. If you use add-ons, stick to what is necessary.
Take it easy Give pages time to load. Graphics take more time to load than text, and require more memory. Video sites, like YouTube, are even heavier on system resources, so patience goes a long ways. Probably the most memory and resource intensive websites are interactive gaming sites. You can play simple games on some of these sites if you take it easy and don't rush things, but serious gaming is not for these older computers.
Other Apps Having one app open at a time is easy on the memory and less likely to lead to crashes or freezes. Before opening your web browser, close your graphics program or movie viewer.