There are 100 different things to learn along the way, but if I could go back to your point, I would say these are the big items in the beginning, and VERY general i.e. big picture:
1) 20% down. If you can't do this, most times you can't afford the house.
2) Get a 15 year note that is around 30% of your take-home pay (gross minus taxes). This is going to put you in a significantly smaller house than you think you should get, so if you're already above this or have a 30 year note, try and save up and make that happen on the next one.
3) If you're about to get married, don't look at your combined income and then buy a bigger house. You never know when you'll need to live off only one income. Save, save, save.
4) Like others have said, find a reputable plumber, electrician and AC guy.
I've bought and sold 5 primary residence houses now in 3 different states, and turned a profit on each one. There are so many factors you can and cannot control, and you need to look at all of them. If you want to get into the weeds and have more specific questions, hit me up. Location dictates so much. Sometimes, trying to make money off it isn't the right move, either. It's simply trying to pay it off. I didn't always follow the advice above, but I always had a reason not to do so. Like I said, it changes from place to place. Are you a short timer or in it for the long term.