I'm a big fan of lessons, at all skill levels not just beginner. I'm still periodically taking lessons after 20+ years riding - mostly to focus on some fine tuning and to break some bad habits from teaching myself and riding for years and years without ever any formal instruction.
On the other hand, this is snowboarding and you just want to go get after it ya' know? Take a few if you are a beginner to get those fundamentals ingrained. Then spend time just riding, just having fun, and pushing yourself. Then go back for a check-up, get an instructor to review all you've been working on and make corrective suggestions or provide more advanced techniques that may help you step up a level. I liked the idea of a lesson early season, mid-season, and end of season, especially for a beginner.