I'd ask why care if they're 'laughing' at you or not?
If you're taking the time to speak to someone in their native language, you're showing respect. If they can't recognize that and help you through the novice learning curve, those people are assholes. The best way to learn another language is to immerse yourself, perhaps struggle a bit and then learn from it.
That you're taking the time to do all of this is pretty awesome to me. Keep it up. And don't be self-conscious about what may be right, wrong or mispronounced. If this guy (or any guy) has some decency, he'll understand what you're trying to do, appreciate it and help you communicate more effectively.