i love shownu so much you don't understand 😍. i also love kpop so if you do, you're my new favorite person.
upload your background (whatever it is that you want it) and the circle as your foreground. make sure to mask all the white out (or whatever the color is) and keep the black outline of the circle. click the transform tab and center it where you want it, then click 'merge'. (the center button is the one with the square that has the arrows pointing to all sides)
go to foreground and click the picture of the celebrity that you want. you don't have to do this, but what i like to do is go to constraints and click the '1:1' option so that it's easier to mask everything else out.
go to the mask tab and make sure to mask out everything except for your celebrity. try using the magic wand first, but if it erases too much of your celeb, then do the magic brush. i had to use the brush for this one because the magic wand would take the white out of my celeb's shirt, and i didn't want that.
go to the transform tab and click 'multiply'
by clicking multiply, it's easier to see what you can mask out now. erase everything out of the circle and be careful not to erase anything inside of the circle. the dark outline of the circle helps a lot to see if you masked out anything inside.
now you can go back to the transform tab and click normal. after this, you can save it and go to phonto add your title!
i hope this was helpful:) i feel like i didn't really explain well on certain parts. tell me if anything confused you and also let me know if you guys have any tutorial requests!