Help! My puppy just vomitted?

I just got my new puppy (10 weeks old) a week ago now. I'm really worried because he vomited, he woke up from a nap and started to make funny noises which I clearly knew something wasn't right. I comforted him while he was making weird regurgitating sounds (looked like it was coming from his stomach area) he made the sound a few times then vomited a yellow looking bile this occured 4 times then it stopped. About half an hour later after playing a little he did the same thing, but it was just mucus looking vomit. He then did 2 poos one normal looking one and the second one within a minute was much wetter, but still in solid form. I know he's been outside in the backyard to do his business which i havent kept close supervision. He hasn't eaten anything bad, just chewed some grass. Any help and assurance will be fantastic!