Although he got off to a rough start, he was able to win the race anyway.
Although she broke her wrist, she can still ride her bike.
Although he hates to dance, he danced with his wife on her birthday.
Athough the field was wet, they still played the Baseball game.
Although Mom isn't crazy about animals, she let the boys get a dog anyway.
No, You cannot use but to start a sentence.
I will now begin the demonstration. Let's begin at the beginning.
They were happy although they were poor.
The solar eclipse will begin at 2:30 pm.
yes
The ceremony is about to begin.
well I think yes because you can start the sentence like this:Although it was rainy i went out with my friends.
You always want to begin a new sentence with capitalization
Use a semi-colon instead
Yes. There is no word or phrase in English that cannot begin or end a sentence.
Although it is raining, I decided to walk outside anyway.
Although it's raining, we can still go out to play.