Please help, only five questions.

Okay so i'm taking an online spanish course (penn foster), and in the study guide, you have to create a bunch of sentences with words you've learned so far. translating, reading, and those kinds of things are fairly easy, but when it comes to making my own sentences, my brain just kinda waltz's away. anyone got any tips?

What’s the subject pronoun for felipe and the correct form ser

Lupe: ¿dónde compraste estos libros? esteban: compré en esa librería que está cerca de nuestra casa. a. los b. la c. las d. lo