Those speakers look like a pair of ported bookshelf speakers. I would be optimistic about them from the pics, but obviously it is hard to know without actually checking them out for real.
The first thing I would do if I were you is check that they do actually work. If they have been in your garage there is a chance that corrosion may have caused problems for them. Good to find someone with a regular Hi Fi amp and connect them up to that.
On the back of those speakers are terminals which look like they will accept banana plugs or bare wire. If I were you I'd get some two core mains cable and use that for speaker cable. This will work very well, it is cheap and will be just as good as cable sold at many times the prices from Hi Fi dealers.
To power those speakers a decent budget stereo Hi Fi amplifier is all you need and these can be purchased at online auctions for very low money because they have been made in such vast numbers for decades. You will be able to pick up a good one for low money. The power output of these amplifiers is usually between 20 and 40 watts per channel. I suspect that those speakers will work fine with that.
Once you have the amplifier hooked up to those speakers there is every chance that you will have sound hugely superior to the 2.1 system you are replacing.
When people enquire about "best 2.1 system" here I often first advise that they would do far better to buy second-hand bookshelf speakers (like the ones you have) and an amplifier, like the one I am advising you to get.
We call the speakers "bookshelf" speakers really just to mean a small speaker. We don't mean to actually put them on bookshelves, you can put them wherever you like :)
If you are using them with a computer monitor it is good to get them up off the desk. Place each on on a pile of books if you have any. Get them so that the middle of the speaker is at ear height. Also angle them in so that they are directly pointing at your head. This positioning will get very much better sound. When using nearfield speakers (meaning speakers that are close to you) the most important thing is to listen to them "on axis".