You got a lot of good advice, but I wanted to add. I rescued my draft approximately 2 years ago. She is 17.2 hands and approx 2,200 lbs, but a big beautiful baby. I rescued her through Gentle Giants Resue. She is a retired Amish Work Horse. I did try her out at their farm and went back again a second time.
When Chantilly came home, I gave her a couple of weeks to get to know the barn, the pastures, the other horses, etc. During that time, she got lots of love, brushing and hand feeding. Then I started riding her. She is great and has had as many as 8 children gromming every inch of her body at one time. The only danger with her is that she might fall over from sleeping. She absolutely loves to be brushed.
But, she is a big girl, so I am always with her when kids are around her.
She did not like her feet messed with. Again lots of paitence. Every day, pick them up, put them down. Now, she is a dream for my farrier.
However, she never has and never will lunge. She just does not get it. And I am ok with that. Because anytime I want to go for a ride, she is ready.
As for getting a goat and having only one one stall. I now have two horse and each has a 12 X 12 ft stall. I also have three goats which have their own house. Tell those goats that Chantilly is way bigger than them, go figure?? Now that the temps are in the 30's. Most of the time, the goats are in Chantilly's stall sleeping at her front feet. I wish I could get a picture. Not every horse will tolerate a goat, but with Chantilly, she is the top dog in the field, the goats now it and she is very careful around them. And for that matter, the ducks, chickens and geese. If you do get a goat, a small house for them that the horse can not get into, I think is still a good idea.
I guess what I am saying. Congrats on getting a Belgian. Give him time, try things out. All horses are different. Not everything works on every horse. Most importantly, enjoy. I wanted a draft all of my life and I have her. Chantilly Lace. It is funny, she does not look that big to me anymore, but the fence she is behind, is a little over 4 ft from the ground.