I feel bad asking for rep.

[Inviss]

If you don't ask, you don't get

 

[ReflexShow]

If you feeling bad to ask for a rep, just ask for a nice comment on your profile with "rep+" and it will be easier for him to do

 

[Konduktor]

i have 0 rep aswell and i just created my account so

 

[gldfnch]

should I ask my past clients or all my ones from now on?

I think, you should ask them.
If someone, with whom I was working ask me if I could rate his job, I will definitely do that. It takes just 5 secs to do