First do not uninstall your Czech version.
For Photoshop, you change the install language to Spanish temporarily in the Creative Cloud app and install Photoshop. That places the UI language pack in your UI menu.
After the install finishes, change back to Czech, and go to Preferences > Interface. Your UI menu should look like so. Select Spanish and restart Photoshop.
I know the only difference is the UI language pack, but for other Adobe apps like Indesign, I'm not sure. Consult their respective forums. You need not change the MacOS language if the photoshop UI in Spanish is what you want.
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