Keeping my tomatoes free of pests

My cherry tomatoes are about the size of a cat’s trouble marbles and going strong, but I just know something is going to come along and feed on them before they make it into my salad.

Also, I was away for a week and when I returned the bottom of one plant had lots to dying leaves/stalks (I’ve already removed in pic but you can see the stumps), so I’m concerned something is already feasting.

I’ve spent about two hours online and am now more confused than I was when I started. You guys have always given me great advice, so I’m back for more.