What workouts should I do to gain muscle and abs?

I do martial arts trainings 3 times a week and yoga 2 times a week. I'm 165 cm tall or 5'5 and weigh 53 kg or about 117 pounds but not happy with my body, what "at home" workouts should I do to gain muscle and "get abs". I have small 2.5 kg dumbells, a pipe thing to do pull-ups on and a skipping rope but nothing else. What should I do?
What workouts should I do to gain muscle and abs?
Post Opinion