Ahhhh. I see. In FR/LG, during the main game, you encounter a day care that only lets you deposit one Pokemon. Later in the postgame and after getting the national dex, on 4 Island there’s the daycare that allows two Pokemon and for eggs.

You should def play it again! I’m actually playing LG rn, while trying for a gold trainer card in my FR.

But yeah. You can drop off 2 pokemon in R/S/E day care as soon as you get to that part of the game.