Answer:
Even if every step seems difficult, you should keep trying, for the best things are worth fighting for.
Compound sentence
I did my very best to write a good cover letter, and I finally sent my application to my favorite company for review.
Complex sentence
Whenever the rain falls, I remember how important the simple things are, and I feel glad to be where I am.
Compound-complex
Step-by-step explanation:
A compound sentence is a sentence which contains more than one independent clause which is linked by either a comma, a conjunction or a semicolon.
A complex sentence is a sentence which has at least one independent clause and a dependent clause.
A compound-complex sentence is a type of sentence which has at least two independent clauses and one or more dependent clauses.