What is causing the yellow spots on my tomato plants?

Hello! Can someone help me with a specific question that an experienced gardener might have about a disease affecting one of their seasonal vegetables? I'm noticing some strange symptoms on my tomatoes and I'm not sure what the problem is. I need advice on how to properly diagnose and treat this issue before it spreads to the rest of my garden. If anyone has dealt with a similar issue before, I would greatly appreciate any insights or recommendations. Thank you in advance!