Sure, download a Linux LiveCD. In fact find a list of the most popular versions of Linux and download all of them. (see DistroWatch)
https://en.wikipedia.org/wiki/Linux_distributionLook at the family tree on the right side.
Then burn these distros to a CD (or DVD) in Windows or Linux or Mac.
On an older computer you likely need the 32 bit version of a particular Linux distro. ON a 64 bit machine you can install either 32 bit or 64 bit. On an older machine you can only install a 32 bit system and it will tell you so.
Learn to set your computer to boot from CD. (BIOS or F12 when the computer starts, different for different brands, Google for instructions about the boot menu particular to your computer)
Wait for 5 minutes or more for the disc to boot. It will be slower than if it is installed on the computer's hard drive.
Then play alot.
Attempt the point and click system installer. Repeat with all the different distro versions you want to try.
Once you find one that you like, start haunting the forums for that "brand" of distro (version).
Learn how to get the wireless to work on your laptop. Then use the web.
Then install and uninstall software until you find what you like for each task important to you.
Whatever you do, don't try this on a laptop that has important data stored on it b/c if you are like me - you'll crash it several times while tinkering. You want a guilt free ability to format the hard drive and go again.
It took me several distros before I landed on Mint Linux. Also I figured out along the way that I prefer the KDE desktop which isn't going to run on old hardware very well. Still - figured out which browsers, which office, which media players I liked the best. Was a period of exploration that made for alot of fun memories.
I'd follow the advice already given in this thread. A Ubuntu or derivative like Mint Linux with one of the lightweight desktops. I'd also recommend at least 1GB of RAM. eBay might be a good source for more RAM at a reasonable cost.
If you use one of the Debian/Ubuntu/Mint distros or derivatives here are some good websites:
Noobslab, LinuxQuestions, the Mint Linux forum, the Ubuntu forum, TecMint, OMGUbuntu, PlayDeb, GetDeb
FWIW I use Google when hunting for Linux help. For whatever reason Yahoo and Bing don't seem to deliver the most helpful results. You can copy/paste error messages from Linux into Google and keep simplifying (shortening) the error message until you find a result that is helpful.
Also, using Google for your searches, constrain the search results to the past year or two. 6 or 7 year old help isn't going to be relevant unless you choose to run 6-7 year old software - which I would not due to lots of improvements each year.
Also - if you have a newish Windows computer you could run free Virtualbox with Linux inside to tinker without the risk of crashing a computer. Google "How to install Mint Linux in Virtualbox".
Play attention to the names of the software that you choose to run. If someone asks which browser or media player or picture editor you use, you ought to know that b/c any help you need will be specific to that software. Don't be like people I've tried to help for twenty years who complain their computer (any OS) is acting strange but don't know what kind of browser they use. To me it's like complaining about a car and wanting help solving some problem but not knowing if you drive a Buick or a Toyota.