Hi SuzEQ 

Timeframes depend on how many hours you want to dedicate to trading? They are quite about the comfort and time you would like to spend.Of course If you're back testing your strategies you can test them in different time frames to find out the most suitable alternative.

TF depends a lot on your strategy-If you are holding position, smaller timeframes of 1 or 5 minutes may not be relevant.Timeframes are really about he trading styles and strategies-for quick gains and losses traders use shorter timeframes.You must have noticed some traders using more than one timeframe at a time to decide an entry.

Time frames are more of a matter of preference.