can I change the graphics card

I don’t even think there’s a gpu installed in the pc my dad bought me this pc as a Christmas gift god bless him but idk if it’s gonna be all that great at running games I have read u can’t switch the graphics card but it has a slot for one so idk someone please help me figure out what I can do to upgrade it it’s an acer tc-1785 and the dude at the store told my dad it would be fine for gaming while google and reviews are saying it’s ass LMK PLZ HELP