Start by learning Hiragana and Katakana. Just do a google search to find them. The 'abc' letter system that you're referring to is a romanization of Japanese called 'romaji'. It's useless. Learn Hiragana/Katakana first - it will take you a couple weeks. After that you can start learning simple vocabulary/sentence structure.
For spoken Japanese, there's a decent site for beginners at
Learn Japanese with Japanesepod101.com
At first glance, it appears to be a paysite only, but you can listen to the audio podcasts for free and start learning simple spoken Japanese. That's the best place for people who can't learn Japanese at a school to start learning simple phrases and whatnot. They have more intermediate/advanced content as well.