Respuestas al mensaje #2

Sounds like you need to re-tin the tip of your soldering iron due to it being oxidized.

They make and sell kits that are simple PCBs you solder and put together yourself to learn the basics of soldering. Look up "Elenco FM Radio Kit"...

You need to apply the flux to the actual thing you're soldering the component onto - flux is how your solder sticks/flows onto the thing you're...