How to create stroke from path?

Dear all,

I'm little confusing of how to create a stroke from path. Here are my steps :

1. I'm creatin an amazing path using pen tools like below :

2. Next, i want to make this line bigger and colorize this line. To do that, i should create stroke by right clicking this path -> choose stroke path.

Until here, am i in right steps??

3. Then, from the dialog, i choose brush.

4. Great, i have create an bigger line.

NOW, I HAVE A DIFFICULTIES :

a. How to change the brush style?

b. When i change my path, my stroke of brush doesn't follow it. How to make it follow the path?

Thanks so much for help.