I'm sterting out with VJB novice weight lifting with my own upper body weight lifting program. I am wondering if I should do strength training or rather increase my muscle mass?

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Height: 5,9"
Weight: 137lbs/62kgs
Reach : 7,7"
Wing Span : 6,3"
Standing Vertical: 27 inches
Running Vertical: 30 inches
Goal Standing Vertical: 45 inches
Goal Running Vertical: 50 inches
Position: PG, SG, SF
Program: VJB Novice Weighs + Stronglifts 5*5