I would advise you simply just to learn the 4 tones by rote from a native speaker through classes or audiobooks. (I'm sure there are also reliable audio clips online.) And then just keep practising. They are extremely important at the outset or else you'll get words and pronunciations all mixed up as you go further up.

Don't use analogies with other languages, especially with (somewhat) related languages like Japanese. Else you'll risk having a heavily Japanese accented pronunciation of Mandarin.