Reply to Messing around with producing

I've been DJing for about 6 months now and am really enjoying it. I want to start producing a little just to get the feel of it. I'm probably just going to use Garageband for now and if I like it, I'll jump into Logic or Ableton. What I'm wondering though... is it bad to use samples from other people? I've been downloading sample packs off Beatport and some royalty free ones off other websites. I'm just wondering if experienced and big time people do this. I'm not great with instruments and plan on looking into music theory in the future...but do all producers create their own sounds or at least most of them?