Purchased a theme on Envato, question about customizing the portfolio section of my website.

Hello, everyone! Last night, I bought a theme from Envato, and it’s almost precisely what I’ve been looking for. Except there’s one thing I wish I could alter or adjust, and I’m not sure whether that’s even feasible!
My Website:https://cancatseat.info/
So, on the main page, I have my portfolio, and if you select one of the categories, it will take you to the albums in that portfolio. I’m wondering whether it’s feasible to have the photos shown in a masonry grid when you click the album. Please let me know if you have any suggestions/recommendations for plugins to add; thank you!

Page speed is so slow, firstly work on page speed. After 2 min, I can’t see any images labeled by you. So, firstly, optimized the images & make a great page speed.