Sure, you can do that. You're a homebrewer!
And no, you're not over your head at all. Porter is a very forgiving style to brew. Check the HBT recipes section.
Many brewers add flavor and aroma hops to porter. I think it'd work better with a robust porter than brown porter. Try adding a half-ounce to an ounce of your favorite hops variety at flameout.
If you're looking for a recipe, try this one. I've brewed it many times and it's always well-received.
Coal Porter
A ProMash Recipe Report
Recipe Specifics
----------------
Batch Size (Gal): 5.00 Wort Size (Gal): 3.00
Total Extract (Lbs): 7.50
Anticipated OG: 1.050 Plato: 12.37
Anticipated SRM: 32.4
Anticipated IBU: 31.9
Wort Boil Time: 60 Minutes
Grain/Extract/Sugar
% Amount Name Origin Potential SRM
-----------------------------------------------------------------------------
80.0 6.00 lbs. Briess LME- Gold America 1.035 4
3.3 0.25 lbs. Black Patent Malt Great Britain 1.027 525
6.7 0.50 lbs. Crystal 55L Great Britian 1.034 55
6.7 0.50 lbs. Chocolate Malt Great Britain 1.034 475
3.3 0.25 lbs. Treacle Generic 1.036 100
Hops
Amount Name Form Alpha IBU Boil Time
-----------------------------------------------------------------------------
1.00 oz. Willamette Pellet 5.00 21.1 60 min.
1.00 oz. Willamette Pellet 5.00 10.8 30 min.
1.00 oz. Willamette Pellet 5.00 0.0 0 min.
Yeast
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Danstar Nottingham
Give that a try! Hopefully it'll work for you. You don't need to use Willamette; you can use whatever hops variety you prefer. Cascades work well.
Good luck!
Bob
