I am currently using ubuntu software and i want to learn photoshop tools, but i can not install in ubuntu because it is valid for only microsoft windows and macOs. So, my question is how i can learn photoshop tools without installing another operating system (that is microsoft windows).
Adobe don't have their applications for Linux. You can try to run Photoshop through Wine but it's probably going to be an old version of Photoshop with limited support. You can see the state of support for different versions of Photoshop on Wine website: