Which product are you considering and what exactly are your concerns about it?
Please ensure your computer meets or exceeds the minimum system requirements to run Creative Cloud + all other apps you intend to use. Check each one. Keep in mind that Catalina alone requires 4 GB of RAM and 12.5 GB of HD storage.
https://helpx.adobe.com/creative-cloud/system-requirements.html
All merchants these days must ensure the bank/credit card is good before they accept it toward subscription payment. The way they do that is by submitting a nominal charge (usually under 1 dollar/euro) to verify the card is not stolen. The fee is then credited back to your subscription account. If you're not seriously interested in using the software/service, do not take out the trial.