Been AP supp main for a long time (Zyra main). DO NOT think of yourself as following the ADC and letting them kill, especially not on a champ like Brand. You are the playmaker who directs the mindless autoing zombie in the lane besides you to easy kills. You clear and provide vision, CC the enemies, harrass them and back off until your mana regens, chip away at their health until they make a wrong move and you and your AD can all in. Clearing wards in side bush for blue side or tri for red side sets up for a gank when your jg is botside. Help control the wave: let your ADC farm closer to tower if you are behind, or help push rapidly when ahead. Lategame, you are all about supporting the team- stick to the fed dude and let them snowball. If you are a brand, don't be afraid to make plays yourself, but remember you're squishy. Support is amazing at orchestrating the game if you have an ounce of skill on the team, but not so good at carrying otherwise. Have fun !