I got my second Moderna on April Fool's Day, 4 weeks after the first.
First jab--sore arm for a couple of days, temp up maybe a degree for about 12 hours.
Second shot--side effects much like a mild case of the flu. First, the "brain fog", a light-headedness that came on suddenly and lasted for less than 24 hours; rising slowly avoids the unpleasantness. Then, minor but wide-spread body aches, pretty much gone now. Finally, a minor (2 degrees) spike in temp, lasting no more than a few hours. Now, 48 hours after the shot, I'm 90-95% and still improving.
I'm happy with how it went. I know of a couple of others who had a very unpleasant couple of days post-2nd injection