From my experiences I think lessons first will go a long way towards understanding how we play on the course, with caveats. This was something I learned personally and my evidence is more anecdotal than scientific but I hope it helps.
When I first started playing I took the advice of lessons lessons lessons seriously. So much so that I signed up for 6 lessons with a well known coach in the area. I drove about an hour every month to take a lesson, so that was 6 months straight of at least a lesson a month.
If I could do it over again I would space them out more. The reason why I say that is because I didn't take enough time between lessons to really absorb what he was saying. I took thorough notes during the lessons and still have them now. What I've noticed is that all the advice and mechanic he tried to teach me took a long time to really hit me. Some of the things he critiques about my swing which seemed inconsequential at the time ended up being breakthroughs as I kept playing. I took my last lesson with him a year ago and just last month one of the things he told me clicked on my head and I've been playing a few strokes better ever since.
Long story short, my advice is to take a lesson first, take great notes, ask all questions that come to your head no matter how basic you think, even record your swing with his advice if possible and then practice. Hit the range and try to apply some of the advice. Play as much as funds would allow and don't rush improvements. As soon as you feel you've taken the lesson seriously I would start thinking about going back along with your progress and the things you've learned along the way. Hope this helps. Cheers!
Sent from my iPhone using MyGolfSpy