UK citizen. Partner us citizen. Not ready for marriage. How do I get over there for work?

Hi,
Very new to this whole thing and have trawled a series of websites, including forums and the official USA immigration website.
Apologies if this has been asked a million times but I have no idea what I'm doing!

I am a UK citizen and my partner is a U.S. citizen. I am hoping to seek employment in the U.S. to be with him but we're not ready to go down the marriage route yet.

I have over 10 years experience in the care sector but no qualifications such as a university degree, not a physiotherapist, occupational therapist etc
Everything I know has been on the job training and I specialise now in support work for adults with brain and spinal injuries.

Could anyone tell me the best route to take to apply for work and which visa to go for?
I did call a few companies in the USA to see if they sponsored foreign nationals to work over there and each one said I needed to be authorized to work first.
But, I have also heard that I first need to find a potential employer before I apply for a visa!

Can anyone point me in the right direction as I'm utterly unsure of what I need to do.

Many thanks.