If you find their locations, you can simply drag them to the Trash. I wouldn't modify anything without a contingency plan though, just in case you inadvertently trash something you need. Among contingency plans, Time Machine is the most comprehensive: Back up your files with Time Machine on Mac.
The next macOS version will be Catalina; yes.
In Apple's terminology, new macOS versions are called upgrades whereas incremental updates to existing versions are called updates. macOS 10.14.6 is its most recent update.
Can I take my MacBook Pro to the apple store to remove?
Yes, but if you don't want to take the time and investigate those apps yourself it would be much easier to simply contact Apple over the phone: Contact Support. You might have to pay them $29 for the trouble.
I really, really wouldn't be concerned about that dialog though.