Let’s look at the things to consider when picking one.

A personal trainer can just as easily be great and uncertified as they can be horrible and certified.

The PTDC explains:

You’re hiring a personal trainer because she presumably knows more than you.

Ask her to tell you about things like muscle confusion and whether you should probably be sore each workout?

No you don’t need to feel sore after each workout.

What this means is that anything different will make you sore.

Muscle confusion is a buzzword that doesn’t really mean much.

Muscles don’t get confused.

They don’t think.

They respond to stimulus and the mechanisms to adaptation are pretty well understood… check that to shop around and don’t make the decision lightly.