Cemetery etiquette

So I live in a semi new area half of my time.

There happens to be some Jewish cemeteries in the area and they look so beautiful and interesting.

I’d love to walk through one, but from the outside looking in, it’s pretty clear that Jews have a different idea on burial so I’m sheepishly asking a few questions out of a real due concern to not disrespect your culture.

1) Is the idea of just walking through a Jewish cemetery quietly and respectfully just to explore disrespectful?

2) Why are the headstones packed so close together?

3) Is there anything you think I should know or do in order to respect these sacred spaces?

Edit:

What sparked this was I was driving past one and I had my work uniform on. I work outside so my clothes can get some dirt. I’m not filthy or anything.

It’s tan pants and a Royal blue shirt which, honestly, for the most part I wouldn’t think twice about walking in another cemetery wearing because they seem so much more informal.

I can only say like my clothing felt “loud” for such a place which is what caused me to ask.