Hello and welcome to Tom's Hardware Forums.
It's hard to give details instructions without knowing which printer you're using but in my HP, I'm offered several choices of print sizes and layouts for multiple photos on one page. When you click to print and select the printer, you should see an Options button or the printer's Properties page and that's where to find the choices.
Post back with the make and model of the printer - someone else will have one and be able to help more.