it's all RNG, but 9 stacks of bonemeal should've given you a few candleberry seeds or candleberry themselves which you can turn into seeds.
I always set up a 7x7 grass platform with an activator pointed upwards under the center grass block and another activator pointing downwards 2 layers above the center grass block
put some bonemeal in the bottom activator, put a scythe in the upper activator set to left clicking and set up a vacuum hopper with a diamond chest and let it run a few stacks of bonemeal