The subjunctive is rare in modern English but very common in French!
que does not mean the verb following it will necessarily be in the subjunctive!
You will need the subjunctive after specific verbs and impersonal phrases such as il faut que [it is necessary that].
When you have two sentences and two subjects, you are likely to use the subjunctive, when the subject in the first clause is having a thought, emotion, wish, desire, or request on the subject in the second clause. For instance, Je [I] in the last example below, have some desire Je voudrais (I would like) on the subject of the second clause tu [you]: the desire being that “you come with us.”
Il faut que je fasse des courses.
I have to do some grocery shopping. [impersonal verb]
Je ne pense pas qu’il ait une voiture.
I don’t think he has a car. [thought]
J’ai peur qu’elle soit déjà partie.
I’m afraid she’s already gone. [emotion]
Je voudrais que tu viennes avec nous.
I would like you to come with us. [desire]