Ranks and stuff.

The ranking system goes b5-b1, after promos in b1 go well, you go to s5-s1, then g5-g1 and so on.

Your ranking isn't based on how many games you win or lose. It's based on your MMR (Matchmaking Rating) at the end of your placements. You start at 1200 (MMR equating to silver 5, the average rank) and gain/lose MMR as you play, with it being based on more than just whether you won or lost. If you only won 2 games and got bronze 1, then you played like a bronze 1 player.

However, after your first placements, your starting MMR for future placements is 1200 + (last season's MMR) / 2. Most players also often get placed lower than they were last year (like how I got placed in silver 5 last year and bronze 1 this year, despite significantly improving in that one year), so it was probably not a good idea for you to finish your placements before this season ended, as this season will be ending very soon. I'd say try to climb to at least silver 3 before this season ends so that next season, you don't fall too far behind.