1) There is no established timeline.

2) You can marry now.

3)a. Getting married is pretty effortless if you're going to skip the sugar-coated nightmare scenario of a giant wedding. Go to the local courthouse, apply for a marriage license, pay the fees, rent an officiant, and you're done. Sign on the dotted line!

Then, your shiny new hubby needs to file form I-130 and form I-480 on your behalf.

3)b. You cannot work until you receive your work authorization and Green Card. That could take a while. My friend from London waited nearly a year after his wedding in Kansas to get those.