Yes, you can use bloom as a verb and blooms as a noun. Blossom can be both a noun and a verb, depending on context. Hope this helps, Elsa! :)

Both can be either a noun or a verb. ‘The flowers are in full bloom’. [noun] ‘Look at the cherry blossom ! ‘ [noun] ‘Just wait until these flowers start to bloom’ [verb] ‘These trees will be blossoming soon’ [verb] Both words are also used metaphorically to refer to people. ‘She’s really blossomed since she started school’ meaning that her personality has developed well and she displays confidence. ‘She’ll be dressed in full bloom for the party’ The expression ‘in full bloom’ means that, like flowers or a tree, she is displaying her finest appearance.

Bloom isn't used as a noun. Blossom is a bit of an outdated name. Both are when a flower's buds open.

They are similar but different. "Bloom" refers that the flower is at its fullest, brightest stage. "Blossom" can be a verb describing the process of a bud slowly opening up into a bloom, or it can be a noun which describes a flower which is in the early stages of "opening" up into full bloom.