The big problem people have with the "clone" boards is that they often use a cheaper USB to serial adapter chip (usually the CH340) that requires the installation of a special driver. The board will not be recognized by the computer until you have installed that driver.
As far as your sketch goes though, there are no special considerations for using a clone. The same sketch will work for an official board and for a clone board.
As for "basic issues", well, just keep in mind that much of the tools, firmware, and documentation you are going to be using, and even this forum, was created by the Arduino company. The only way Arduino will be able to get highly qualified people to work full time on producing the resources that benefit all of us so much is by having the financial resources to pay them. If we want to ensure that continues to happen then we all need to find some way to contribute to that cause. Buying official boards is one way to do that, but certainly not the only option.