In one of those realities I have 3 bisexual wives, a blonde, a brunette and a redhead.

My first floor and my attic are different levels of reality. When I’m building something, I “measure twice and cut once” so I don’t end up with alternate dimensions.

There's a multi-verse theory in quantum mechanics. It's still just a theory, but it purports that there is possibly an infinite number of universes in which every single possible outcome has occurred or will occur. If that's true then I think it also puts a squash on the theory of us having free will.

There is no solid proof yet though.

As far as there being different realities? Our existence is based on our perception. What's real for someone might not be real for someone else. Schizophrenics are an extreme, but good example of this. When they have episodes, sometimes they hallucinate and can't tell what's "real" or not. But if you perceive something to be real and can swear it's there, then it's real to you. People with Alzheimers is another good example.

Our brains are receivers and they project what we see. It just depends what frequency we're on. I suppose there is a general frequency that we're all on, and then frequencies in between those frequencies that differentiate all of us. None of us have seemed to be able to expand past that general base frequency yet.

I think therefore I am. Descartes most haunting conclusion for anyone that has given it enough thought. The reality you experience can never be universally conclusive.

Take people with synesthesia for example, I have a friend that went most of her life not knowing that not everyone sees colors corresponding to certain sounds.

The only thing that you can ever be certain of is that you exist, even if it's as a brain in a jar...

As for alternate dimensions, no one has created any passage to one in a lab or their basement, so if they're out there they may be inaccessible and if that's true then they might as well not exist at all from our perspective.

Nope.

There are many different galaxies... so I do believe there could be different dimensions. And like another commenter said.. the ant's perspective is different from ours.

This is an ontological question, a question about "what is".
My personal attitude towards ontological questions is that only that exists of which a significant number of intelligent people can agree that at least one but better several of the following conditions are fulfilled:

1. there is measurable direct or indirect evidence for it to exist
2. adding its existence to our theories allows us to make more or better predictions about reality
3. its existence makes sense as part of current rational theories about other and related things
4. its existence does not contradict any other scientific facts
5. our theories would be weaker without assuming its existence

I do not even know what "different levels of reality" could actually mean, so I will pass on that one. However, "alternate dimensions" can have a scientific meaning, maybe one that is different from what your intended meaning is. But several physical theories postulate the existence of alternate or better additional dimensions because their existence would allow for better or "simpler" theories about some of the fundamental physical laws. However, so far, there is not enough scientific evidence for them, in other words, we cannot really claim that any of the above points 1-5 are fulfilled strong enough so that we can all agree that it would be a better way to describe or think about reality.

It's the only reality that I know.

It's the only reality which has any effect on my life.

So, personally, I don't care if there are or not.

Matrix ideas are interesting but I find to be of little value - I leave that to philosophy students!

No reality is reality. No dimensions.

Yeah, but many here would ignore such evidence. Can you accept the Mandela Effect is real?