Hi!
It is great that you're cautious about your diet and you wish to work upon it.
So about supplements, ideally I cannot suggest you before knowing your diet recall. Supplements are appropriate when your body needs are not going to be fulfilled through your diet. So if there's is anyway you can work on your diet more, that would be a better option.
If you have to start with it anyway, I would suggest you to start with one capsule a day. The dosage will also depend on the brand. The same about multivitamins.
Next Steps
Book a consultation on Practo for a personalized diet plan for your goal.
Health Tips
Consult a nutritionist before starting with any kind of supplements.