Hi and welcome.
In game there is the Grid network. This is pretty much common info and the Sindome site has a wiki / help section. These sections can give you some info about the game.
Also, @newbie will help you with some tips.
There is a section in the grid that has some city maps for the Central sections of the Dome. They aren't complete but have the streets, blocks, major business places that people go to.
Remember to read the information on your screen. Different blocks have similar visuals but there are differences.
Yes, Examine commands and the Look commands will help you a lot.
You do have a 2 week "safe zone" to explore and meet people without having to worry too much depending on what you're doing.
You may come across characters that are assholes or idiots or annoying brats but can be clever and are interesting, but keep in mind that IC attitude and flaws are different from OOC. The players tend to be quite helpful even if their characters are selectively helpful and with a plan or don't give a shit about you at all.
(I've noticed that players will have their characters meet up or reach out to new characters though so put yourself out there.)
Read up on @Notes and use those and know that your character is learning. Not a badass to begin with but one hell of a badass in training (in whatever subject / archetype you choose).
And if you're not sure about the direction you're taking, as I've been told recently, more or less it was you can always try another direction with your same character, even a short lived direction, or try something new.
I know of a few characters who have been Mix, Topside, Mix, Topside, and continuing this cycle, and seen another or two try a few directions and attitudes and even personalities until settling out.
You can develop quirks or major flaws as you play and create some exasperation (which can be funny as hell) and then have your character be working toward not having those flaws, be they fear of fighting, communication and social setbacks, nervousness around computers, whatever you like.
Characters are like Shrek and the onion analogy. There are always layers.
Have fun with it.