What lead-free solder type is convenient to use for hand-soldering?
Lead is a magic element that makes solder melt at a lower temperature and protects the tip of your iron against oxidization. Too bad it is a potent neurotoxin.

Most lead-free solders have high melting points. (Bismuth solder paste is lead free and has a lower melting point than leaded solder, but because it is a paste, using it with an iron is not very convenient.)

Without lead, and at higher temperatures, tip oxidization is your #1 problem.
That means shutting off your iron immediately when you aren't using it. Don't let it bake. Some fancy lead-free irons have an auto-setback that reduces the tip temperature when it is placed in the cradle.

And stay away from "CLEAN" solder! Water-soluble flux is very aggressive but corrosive! It will eat vias and traces if it is not immediately cleaned off (should be called "MUST CLEAN"). It is only used by industrial processes that include an ultrasonic bath after soldering.

"NO CLEAN" solder is what you want and means the flux is not corrosive and does not need to be cleaned. Yes, the terminology is confusing.

FWIW I like Kester Sn96.5/Ag3/Cu0.5. The fumes are no worse than lead solder.