Low quality solder makes soldering tremendously harder. If you have trouble soldering the reason is most likely to be the solder you use. If you want to have better quadcopter building experience, invest in good quality lead solder!
Soldering is an essential skill in building and repairing a quadcopter, RC plane and mini quad (commonly known as racing drones). Soldering is basically joining multiple conductive metal parts together by melting and flowing solder between the joint.