Intermission: Spelling irregularities
Japanese has a small number of spelling irregularities. These irregularities make written japanese easier to read, not harder. Particles: When the particles は, を, and へ are spoken, they're pronounced as "wa", "o", and "e", not as "ha", "wo", or "he". Actually, "wo" is still correct, and you see it all the time in singing, but it sounds silly in normal speech.
Words: The word 言う いう, meaning "say", is pronounced ゆう when in the simple tense (dictionary form).
Japanese has a "pitch accent" system, where words have a specific change in pitch (or none) that distinguishes them. This is not the same thing as stress or tone.
Pitch accent is not represented when japanese is written in kana.
Pitch accent is actually very important if you want to speak, so you're going to have to find a resource for that if you want one.
Japanese isn't "robotic", "monotone", or "flat". Japanese has prosody, just like english. Every language has prosody. Prosody is the natural "musicalness" of language.