Great to start habits and a prayer life now that you can sustain throughout your lives together.
Mass is of course the most important thing. Make it the highlight of your week. If you can, try to get to daily Mass as often as possible, even if it is not at your home parish.
Start a simple routine of morning and evening prayers that you and your dh can say together. Perhaps just a morning offering and an evening rosary (start with just 1 decade even).
I have found that time together in the morning really helps my dh and I stay connected. Now that our kids are older, we still say morning prayers together every day. That means that everyone gets up before the first one leaves the house. [Thankfully no one has that crazy commute that means you ned to leave at 5am!]
As for a home altar, you can put one together, but remember that when you start having babies that precious statues and lit candles will not be a good combination! I did make sure that each child has a crucifix in his room, and when they got older we added a statue of Mary to the living room along with the crucifix on the wall.
Your habits of prayer will be much more important than your decorations to raise a child who know from babyhood what it means to be a Catholic.