The focal length of a lens influences two important aspects of photography. 1)Angle of View 2) Degree of magnification. Each image you record takes on the characteristics of the lens you use.
At the heart of any starburst effect is a small, bright source of light which is surrounded by a relatively dark area. To make one for yourself dial a small aperture opening. This is crucial.
Macro or Closeup filters are the cheapest way to shoot macro images. You could easily attach a filter onto any lens you already own and start shooting macro images.
The 35mm lens is undoubtedly a great contender for your travels photography needs. Not only is the lens small and light, it is as versatile as you would want it to be.
Put very simply, focus breathing is the tendency of a lens to automatically zoom out when changing focus from infinity to a close subject or vice versa.