Because of economic downturn in the world, most people have become jack of all trades and master of non. learning skills and not getting a mastery of them because they are testing waters on which of them will eventually pay the bills. I have a friend who during her spare time learnt soap making, baking, sewing yet she's not making money off these skills.
There is need to carry out research before leaning any skills, you need to know what is in demand in your area and if the industry is saturated before going ahead to learn it, if you learn what is very common and almost everybody is doing it, you will hard make it. It is not necessary to learn different trades or skills at the same time, you need to know what is profitable and focus on it, when you start to make profit from it then you can look at related skills to improve and diversify on what you have on ground. Learning different skills that are not related can be very stressful, it is better if they are related so that you can share some tools and have similar clients.