Unfortunately Id recommend getting off of thresh until you climb to mid silver. Thresh can carry but not in the damage sense that is a priority in bronze. You cannot trust your teammates to follow up on an engage, to click the lantern, to position around you, to let you last hit with relic, and the list goes on. Thresh is an amazing champ but he is amazing because he enables teammates. Its just not sound advice to tell you to try different things on thresh in the rank you're at.
Unless you're building damage on him.
Take it from someone who last year was brand new to the game and thought I was good at support. I was stuck bronze 3-5 for half the season then started playing brand/zyra and climbed to gold with a 70% winrate playing support. Did it again this season. My support is again at around 70% winrate but unfortunately i decided to try to be an adc main for the first 140 games and had a staggering 34% winrate lol. Im gold again in SoloQ and its exactly because i went back to brand/Zyra.
Once youre high silver/low gold, you can expand your pool a bit because people start knowing whats going on. Before that though, its like playing russian roulette with teammates.