If you just got your first firearm - that Marlin 795 - I would wait a while, shoot it first, get to know firearms, and only then start looking at other guns. No offense intended, but at this stage of the game you don't know what you want yet or why you want it, and you could rush in and make an impulse purchase that might be the wrong choice.

First you have to ask yourself, "Why do I want a shotgun?" Do you plan to hunt? Want it for self defense? Trap/skeet shooting? All of these things will make a difference in what you ultimately choose. If you have no plan or defineable need for a shotgun, you might consider something else as your second gun. A .22 handgun might be a more logical choice. Leave the shotgun for gun #3 or #4 unless you can specifically say what you want it for. I think everybody should own a shotgun in their collection, but maybe not as gun #2.