Board Thread:General Discussion/@comment-31246660-20180322124320/@comment-28157605-20180727000233

If you take another follower, yours will be dismissed and head home (Whiterun jarl's palace or Breezehome if you bought it in Lydia's case). You can rehire her whenever you want. Also you can marry or hire a steward in the order that you want, it doesn't matter.

After the ceremony, your spouse will ask you where you want to live. You can choose between her home or one of yours. That step is buggy but pretty important since if you don't do it the character you married can just dissapear so don't hesitate to reload. Of course if it's a house you builded, you need at least a bed.

You're right to build it yourself, you will level as you level your smithing skill. Stewards are essentially good at being another blade patrolling your domain and to hire people/buy animals to animate your home so yes, no need to hurry.