Photoshop is a paid program. Thus, it is not possible to use it free of charge. If you wish to use this tool daily, either personally or at work, you must pay a subscription. It can be paid on an annual basis with monthly payment, annual with a one-time payment, or monthly. Photoshop, which is currently managed by an application called Creative Cloud, from where subscription payments are controlled and software from Adobe is updated, will be automatically activated as soon as the first payment is made.
However, if you do not want to pay for Photoshop, you have some alternatives. First, you can use the seven-day trial that Adobe offers to all new users. Please, note that if you have tried Photoshop in the past, you will not be able to take advantage of this grace period again. Obviously, during the seven-day free trial, the application behaves, as usual, making all its tools fully available to you.
Secondly, you have the possibility of downloading Photoshop Express. This miniature version of Photoshop can be installed from the Microsoft Store. It is also available on mobile devices. With it, you will be able to perform basic editions of your images and photographs. However, it falls far short of the functionality of the regular version of Photoshop.
Finally, download and install GIMP. This program is completely free and open source. Also, unlike Photoshop, you can use it on Linux. It has most of the features of the Adobe application and can meet your needs in most cases. It indeed requires a certain learning curve, but it is well worth it given its advantages.