Leaded is easier to solder with, lead-free is less bad for you, but inhaling any fumes from burning stuff isn’t good for you, so use an extractor/filter no matter what.

Personally, I learned on lead-free solder and the rosin core is almost always enough flux for me aside from rework. Always use an extractor/filter either way.

Lead-free. Lead isn't worth it, especially if you're doing this at home.

The choice of flux used is probably more important. Aggressive fluxes are easier to solder with, but leave behind a acid residue which can be problematic for electronic circuits. Fluxes preferred for electronic applications are the least acid, but not as easy to to get the liquid solder to bond.