US Employment based visas?

Hello I got a question concerning the employment/work visa. I'm actively looking for a sponsored job in the US. I've looked on various websites for jobs that are specifically sponsered by employers however I haven't found any job I'm interested in. Therefore I'm thinking about applying for a job I'm not really interested/ which is not suitable for me if it means getting the green card as I really wanna live & work in the US asap on a permanant basis. My question is if I apply for a job that is unsuitable or I'm not interested in & the employer agrees to sponsor me can I then quit my job after a few months or a year (once I've got the visa & adjust my status to permant resident) & then look for another job that I'm genuinley interested in?? If the employer hires me & sponsors me for a work visa how long do I have to stay in the job if I don't like it?? Am I free to leave when I want or how long do I have to wait before leaving?? I know it looks like I'd be cheating but I really can't find any suitable jobs which are sponsored for an employment visa?? All the sponsorship jobs I've found are either out of my area of expertise or are not suitable for me so no judgements please Thank you in advance for your help