My program typically has us begin seeing clients our first semester for assessment (therapy tends to come later unless you have prior experience), although it varies somewhat by lab/advisor. In general, it's a very "med school philosophy" mindset (i.e., watch one, do one, teach one). However, I also know from information posted here and from speaking with students in other programs that this isn't at all the norm, which tends to be that clinical work is started in the second year.
I agree with Maedothin that seeking guidance from upper-level students is probably going to be your best bet. Ask them what problems they ran into and how they went about solving them (or wish they'd gone about solving them).
What I will say is that no matter how long you wait to see a client, you're NEVER going to feel fully ready. You're going to need to essentially force yourself to take the plunge while accepting that you're going to be uncomfortable and will probably make a mistake or three. Just be honest (with yourself, your supervisor, and the client as appropriate) when this happens, learn from the mistake, and move on. And realize that this skill will improve with practice, and will be essential as you continue through your training (trust me, the nervousness and feelings of uncertainty will probably return when you start a new practicum in a different setting/with different clients, when you start internship, etc; the more ok you can be with hitting the ground running despite this nervousness, the better off you'll generally be).