I wanna buy the Photoshop now, but I'm pretending to change my computer very soon. If I buy the software now and install in my courent computer, when I buy the new one, can I install in the new one with the same licence with no further charges?
Did you mean "intending' in place of "pretending"? Assuming you did, the short answer is yes.
If you're buying a perpetual license for Photoshop CS6, you will want to deactivate the software on your old system before installing it on your new system.
If your plan is to join the Creative Cloud, all you need to do is log out on the old system and log into the new system during the new installation of Creative Cloud with your Adobe ID.
I'm not sure where you're planning to buy your license, but I suggest against sources other than Adobe themselves. There are many counterfeiters / scammers out there.
Thank you for the answer and sorry about the "pretending". In portuguese, "Pretender" is "to intend".