Beyond the sibling comments about the flux being the nasty part of solder, and the part in solder fumes that are hard to avoid breathing at least a bit of when soldering, eutectic leaded solder is soo much nicer to use than the lead-free stuff. It melts at a lower temperature, and melts/hardens all at once, making it dramatically easier to avoid bad solder joints. In particular, lead-free solder will really make you despise a cheap soldering iron.

But yeah, be careful and don’t eat solder flakes, and wash hands after soldering.