Here are the answers to your questions about the future tense in Spanish:
Question 1: What does the future tense express in Spanish?
Answer: Actions that will happen in the future.
Question 2: How do you form the future tense for regular verbs?
Answer: Use the infinitive form of the verb and add the future tense endings: -é, -ás, -á, -emos, -éis, -án.
Question 3: Which of the following is the correct meaning of the sentence: "Yo estudiaré mañana"?
Answer: I will study tomorrow.
Question 4: Which sentence correctly uses the future tense?
Answer: Ella estudiará para el examen.
Question 5: Which sentence correctly uses the future tense?
Answer: Nosotros hablaremos con el profesor.
Feel free to ask if you have more questions!