Help identify these items attached to mains water just after the stopcock
There's some funky plumbing going on there to be sure...

Of the circled devices, #1 looks like a filter of some sort, but that's a nasty way to align the cartridge in terms of having to replace it. But it also appears to have a seal tag on it, as in something official? You might be able to get an answer from the water company on that one.

Circle #2 looks like the pressure regulator valve. It keeps the higher pressure of the utility lines from damaging your internal plumbing and fixtures.

If you can shut the water off at the street, you can remove the stem from that main valve and just replace the washer, seat and packing.