Download and print the Hebrew Vowels worksheet. Vowels are separated in the sheet according to class ["A" class vowels, "E" class vowels, etc.] Pronounce the letters with their vowels sounds as you write, You can hear the sounds demonstrated as you work through Lessons 8 to 12.
Remember that the letters aleph and ayin are silent letters. They have no sound of their own but simply "carry" the indicated vowel sound.
Page 3 of the practice sheet includes the main diphthong sounds and oulined in Lesson 13.