As soon as you install the tidal desktop on your PC, you'll get an application to use it. Click on it and this will show a list of all the programs that TIDAL is associated with. This list includes all of the installed applications on your computer. You can see here, which ones are there. Once you've done that, you have to choose an application to download and install. Just click on "install" button and then it will proceed to download and install the file for you.
Once it's done, click on "free" button. A popup window will appear to let you know that you are now signed up for TIDAL. You just need to click on "continue" to finish the process. Then, you will be given the option to install the software. Before you do this, it is better to understand what is being offered in this version. The only "free" feature is the audio player. After you install the software, you can check if your computer is not infected with any malicious software by performing a virus scan.
Downloading and installing the software will cost you a certain amount of money. However, it is worth the price as the software is free. This is not a scam, but just a "trial" period for a certain product. As long as you don't want to renew the membership, you will have to pay the price to continue.