“Actually, I'm looking to switch careers.”

You are talking with someone you just met at a party. You're talking about your career. You've told her about your current job, but you want to get a totally different job. You tell her:

Actually, I'm looking to switch careers.

Actually

You can start a sentence with "actually" when you think that what you're going to say will be surprising and unexpected to the listener.

I'm looking to (do something)

This phrase means that you want to do something. But when you say "I'm looking to (do something), it sounds like you are just starting to make your decision. It also sounds like you are going to take your time. You use this phrase when talking about making large decisions like buying a car or changing your career.

switch careers

Your "career" is the long-term history of the jobs you've had and the ones you will have in the future. When you talk about your "job", it brings to mind the everyday activities you do at work. But when you talk about your "career" it means the choices you make about where to work and how it will affect your future.

To "switch careers" means to change to a totally different kind of work. For example, you can "switch careers" from being a nurse to being a painter.

When you get a different job that's similar to your old job, but with a different company, you say that you "changed (your) job".