Yes, you can breed to your own mares. You need to buy at least the mare barn facilities for your inside breeding. You need the stud barn purchase for outside offers.
Now, assuming you have that and still don't have offers, it is because the stallions don't have enough offspring of quality. I have two studs. A multiple G1 winning HOTY (horse of the year in a category), with no offers. But his first full crop is two now. His sire however I also have. He has no Group wins at all, but was group placed. In addition to the son I have, he has a daughter who is currently another HOTY. The non-group winning sire of two HOTY's is even being sent group-winning mares on a regular basis now!
When you hear the phrase that So-and-So-the-Winner is being retired to stand and "Stud Whogothim is proud to have him and he will be well supported in his first season" means ... they have mares themselves they intend to breed to him. Some of those mare are probably nice quality to launch his career.
Example:
https://www.racingpost.com/bloodstock/t ... ion/360695Talks about this.
Quote:
"We're very proactive with Army Mule - we believe in the horse. We're going to get outside support, but we're not going to rely solely upon the public to justify our opinion," Sikura said. "We're going to support him with mares and stand in there and make sure the horse is breeding the kind of mares we want and the volume of mares that give him the best chance to make it."My Graded-placed stud didn't get any bookings until his second nice winner, and that was because I bought Group winning mares for him, and those foals were from them. Something I can afford in a game only! But, that's how it is done.