Title. For example inside Dead Men's Respite (I went there for bard's college quest before starting dragon quests and learned the 1st word of Whirlwind Sprint but there was no dragon then), if I go back now that I have done the 1st dragon fight quest will there be a dragon to kill inside so I can get another dragon soul?

Interior dragons are pretty rare...

But exterior ones, they're a dime a dozen. They always respawn at walls.

The ones that respawn at the exterior walls don't give additional souls though right?

There is one that I know of......
Down in Black reach you will see a fort in the middle of Black reach, and in the center of that fort there is a big globe chandelier. You need to hit it with unrelenting force and a named dragon will circle around and land a short distance from the fort, you do need to go up a few floors in the fort to be able to reach the chandelier with your shout but there is no word wall that I know of in Black reach. Just a heads up this dragon is made of tougher stuff then the normal ancient dragon so proceed at your own parallel

I have had a few Dragons not give a soul on a return visit to a wall I had already been to, but most of the time I have been able to get multiple dragon souls from the exterior word walls. If you find an area that has Mammoth bones strewn about, there is a chance of running into an exterior dragon later in the game, Bleak Falls Barrow has yielded a dragon on exit if I had a character reenter the Dungeon after completing the Main Questline.

There is a Dragon in Labrynthian, but it can't fly.

and that dragon is skeletal