How can I use this LCD TFT screen as a (wired) second display for my Windows Laptop?
Solution 1:
Your monitor accepts a composite video input. This is an older analog standard that was pretty ubiquitous on TVs, VCRs, and DVD players in the late 80's and throughout the 90's, and is probably not as common as it once was. I'm not sure composite video output was ever common on laptops or graphics cards.
But there are dongles that convert from any video standard to any other video standard these days. And there is such a thing as an HDMI to Composite converter. Just enter "HDMI to Composite (RCA) Converter" in your favorite search and you'll see plenty of options. This is the first thing that came up in a search, but there's no model number or anything and I can't vouch for it. Just an example.
Note that you'll have really low quality with this, but it should be fine for watching video or possibly playing old games in emulators.
Why is composite low quality? Composite combines the color information and luminance (brightness or black-and-white) into a single signal, which has to be "extracted" by the other end. The color information distorts the luminance information, resulting in color fringes, colors that don't look good next to each other on the same line, and high-resolution black and white stuff like text smearing into color. The Wikipedia article on composite artifact colors explains.
Solution 2:
That's not what you would really define as a 'monitor'. It would best be described as a 'TV' without a tuner.
It takes composite video, which is a rare output from a computer these days.
As mentioned in comments, you can get an adaptor.
I'd save your money & get a second hand 'real' monitor instead. The picture quality on that screen will be poor, at best.
From the advert - the screen resolution is a meagre 480x272 - your laptop will be at least 1920x1080 I would think. That's not even old analog television quality, it's about half your old "big TV in the corner that took up half the room" quality.
Avoid this product. Please.
Solution 3:
From your question it seems like you're looking to add a second screen to your laptop and you haven't purchased the car panel yet. If that's the case, I'd recommend that you ditch that idea and rip apart an old/dead laptop that you already own and salvage the screen in it or you could buy a cheap panel from AliExpress or Amazon along with its control board.
The panel and control board is all you need (besides a power source) to be able to connect it to your laptop via the HDMI port. If you're into DIY, you can build this yourself. Take a look at this video by DIY Perks (linked below) which is a tutorial on doing exactly this. However, before you do this, I'd recommend looking up the price of a cheap 1080p external monitor with HDMI input.
If you find that the cost of an external monitor that you can buy off the shelf is just as much or less than the parts you'll have to buy/salvage to make your DIY second screen, there's no point in taking the trouble and you could just go buy an external monitor. However, if it's cost effective to build one yourself and you have the tools for a DIY project, go ahead and build one.
Here's the video I mentioned: Build a DIY screen out of recycled parts for cheap