Which exercise should I do?

EXERCISE
Stretching video
https://www.youtube.com/watch?v=6Y4SaOyWkvM
Basic1:
https://www.youtube.com/watch?v=q20pLhdoEoY
Lower abs:
https://www.youtube.com/watch?v=FTnzhSWAxC4
Chest and triceps :
https://www.youtube.com/watch?v=M76qO1ziCjw
Legs HIIT:
https://www.youtube.com/watch?v=HIdxYCrqLQg
back workout (some with weights)
https://www.youtube.com/watch?v=a_jTAJKpT2w
Beginner back workout
https://www.youtube.com/watch?v=uLUmIjYVUoA
Bicep peak
https://www.youtube.com/watch?v=NftbyLKI0So
Calf  Strengthening:
https://www.youtube.com/watch?v=wPegcOQaKy0
Chest and back with weights:
https://www.youtube.com/watch?v=yesxCg2_bhA