First brew ever all grain own recipe

Hello everyone, I just recently returned from a trip across the pond and while I was there I read about 12 books on brewing from John palmers how to brew to dogfish head brewing extreme brew so I figured I'm an expert brewmaster and wont have any trouble jumping I all grain with my own recipe for the first time.... Well truth be told, even though I have absolutely no idea what I am actually doing I have had a blast doing it. The first brew was a Märzen style pumpkin ale, I think my OG maybe a little low(1.047) for the style I was trying to replicate. I used 7.5 lbs of two row, 1 lbs of heavy Carmel malt, 1 lbs of Belgium special b malt, and about 4 lbs of roasted pumpkin to the mash....any thoughts? Thanks everyone.

That's an ambitous first brew. Way to go! Don't worry too much about the OG being off for the 'style', I don't think Marzkin is an official style.

+1 for what TNGabe said....that being said, if you want to understand how to nail your expected target gravity nearly every time, (with a bit of practice/knowledge of your system) read "Designing Great Beers". Once you have basic brewing mechanics down, this is THE book to understand how to develop recipes, and proactively predict if you'll be high or low when there's still time to do something about it, and know what to do. :rockin: