Welcome to Dakka, and welcome to painting!
Don't let douche canoes like that customer at your
FLGS put you off. Everyone starts somewhere. See my P&M blog (in my sig) to see just how bad my first minis were. I'm not the greatest painter, there are plenty of better painters on here to give you advice, but happy to point in the right direction to try to help!
Firstly, those basics you've got are a great start. Also, the models you've done so far look good. Great first models!
Some advice - this is a great video -
https://www.youtube.com/watch?v=enUqWuU-Nns - if you haven't seen him before, this is Duncan from
GW and he's done a load of good tutorials. This one is Imperial Guard, but it's more about showing the basics of thinning, washing, layering, highlighting, than about the models. If you want to find a video for a specific model or colours I'm sure you can, but this is a great intro on the basics of painting.
The second piece of advice I have is to look at entering
the Dakka monthly painting competition. It forces you to focus on getting something finished (a problem I sometimes have), but also the guys on there are great - a real range of styles and abilities, and they'll really help with advice and motivation. I think next month is Space Marines - not sure if that'll cover Chaos Marines, but probably will.
If you have any specific questions about a colour, technique etc, post it on the Painting & Modelling forum.
Oh, and don't look too closely at the photos you take. I have the same thing - they show up every little problem and mistake and just make me feel bad!