Thank you so much! There’s actually a kit that Lego sells to do this called the Mosaic Maker. It comes with the little square studs in 5 colors (yellow/white/light grey/dark grey/black) and a big base plate to put them on. You put the photo into the online software and it spits out a mosaic. It was trial and error for a bit to find a photo that worked well, but once that’s done you just print it out and snap on the pieces according to the layout. Overall it was very easy, albeit tedious.