I took a couple weeks last July for a program the local university's English department runs. Honestly, I was skeptical – figured it'd be a lot of theory and not much actual writing. But they made us write every single day, short bursts based on weird prompts, and then share in these tiny groups. The pressure to produce something, anything, for the next morning was surprisingly useful. It broke my habit of over-editing the first paragraph for hours.
They also brought in a few agents for Q&As, which felt premature for me, but hearing what makes a query letter fail was invaluable. The whole thing felt less like a lecture and more like a boot camp for getting words out of your head. I left with about thirty pages of messy, disconnected scenes and the nerve to finally call myself someone who 'writes.' The social aspect, just being around other people who were also nervously sharing their work, was half the benefit for a beginner.