Canadian Rn working in the states on a work visa

I am a Canadian Nurse working as a travel nurse in the usa. I am engaged to a US citizen and want to marry, if we apply for the fiancee will that affect my ability to work in the usa

Not if you time it correctly. It takes about 3 months to migrate from TN to EAD after marriage. During that time you CANNOT leave US for any reason, or you will not be readmitted, and/or will not be allowed to work. And you need to make sure that your TN is valid throughout this period.

So, you marry in US, honeymoon in US, file I-130/I-485/I-131/I-765, and stay put at your job until your EAD comes through.

visajourney.com has infor on marriage based AOS, but be sure to look for specific info dealing with those who are on TN.

What AGN said. You do not want the actual Fiance Visa (k1)

Yeah, just to clarify, I'm talking marriage here, fiancee stuff doesn't apply whan you are in US.