Biggest difference I found moving from Europe was that you can make a right turn on a red traffic in many states in the US (but not in New york city apparently!). You have to treat it like a stop sign and yield to any traffic on the road you're joining. Ends making a journey of rights turns much fast than one with left turns, particularly in rush hour

Left turns cross all four lanes of traffic involved in an intersection while right turns involve two, so if either street is busy you have to wait longer for a gap.

Roads can be very wide in the US, it is not uncommon for cities to have 6 or 8 lane roads at-grade (i.e. not expressways). So when turning left, one must turn across 3 or 4 lanes of oncoming traffic, instead of just one as when turning right.

Yes, I'm in the US. Left turns have to cross oncoming traffic so you have to monitor both directions. This is especially stressful if {both roads are busy, there's weather/dark, you don't know the roads}.