The various modes that a radio can be put into really don't matter but it is recommended to use the same mode that others in the area you live in also use so if you get help, it will be more relatable during the help/training. For instance in the USA most will use Mode 2 and areas of Europe often use Mode 1.
Flashing light? ... on what a flashing light could be anywhere and would depend on context, make/model of what it's on and even color. You should also provide which make/model of radio you are using so anyone trying to help may have context for that as well.
Helicopters are not a beginners aircraft. They are often said to fly like if you were trying to control a spinning marble on a tilting glass table. The smaller the aircraft, the "twitchier" they are to control.
It is always recommended, even if it's an airplane, that you first train on a good computer simulator or get training from a good pilot directly.