Need advice on how I can change projects?

[ornate osprey]

I have never used that language before nor do I enjoy coding in it. If I was told I was going to be working on this new tech stack I would have never accepted the job... Do I tell my manager that I do not want to work in this project?

Yes, it is good for them to know your preferences. And if it's to the point you're considering leaving the company, then absolutely you should be telling your manager first. They can't fix it if they don't know there's a problem.

I would not start with the assumption they lied; I would start with the assumption that plans changed between the time they were talking to you and the time you joined

Because that's a thing that happens, and because I like to start with assuming the best of people until they prove me wrong