Answer:
If you wanted to run faster, you should have eaten breakfast. It is a conditional sentence.
If she were to skip breakfast, she would not feel well. It is a conditional sentence.
I really hope that he remembered his wallet. It is not a conditional sentence.
Step-by-step explanation:
The first sentence is a mixed conditional stating something that the person should have done differently to have a different outcome. The keyword that makes this sentence a conditional one is IF, which is stating what has conditioned the main clause.
The second sentence is a second conditional since the first part is the if clause in the past tense and the second part has the modal auxiliary would. It is stating a hypothetical situation in the future.
The third sentence is not a conditional one. It has a main clause and a subordinate clause that is expressing a wish, but there is not a clause conditioning the other.