1. The most important things to focus on is agreements and decisions with your partner, and by that i mean having honest conversations with each other and what each side expects from the other after marriage and what he wants from him as a life partner and most importantly the "DO NOT"s because its vital , because most couples when they discus their future they only discus  their biggest plans and what they wanna do and forget or had thoughts about "WHAT IFs" but never bring the subject to discussion and want to stay in their state of sweet love and their image of happy life, but then after marriage one of them wants to do things his partner doesn't agree with, so problems begin to rise in their life and that could ruin their life and their marriage even very early, to wrap it up "love alone can't build a happy home so discuss everything in details".

2. The second thing to assure is that you have a stable financial income, although this thing is obvious because you can't build a home if you can't afford even feeding your family, so you must have an income even if it is small you must have it to begin with.

That's it, so don't always focus on the financial side, money won't give you happiness, money at the second place, honesty and wisdom at the first place.