Hello. I have few question as a newbie bonsai owner. I got this firethorn yesterday. I read after it, and a decided I gonna keep her inside until late spring, the question is can I prune back now or I have to wait spring? I planing to make little tree's from the cuttings, if I cut them, and leav the cuttings in water they gonna rooting?

Welcome to this forum.
Yours is a very young firethorn, and not trained at all.
Where are you located? Southern Hemisphere? Northern Hemisphere? USA? Europe? Japan?
If in your location winter is arriving, don't prune it yet, wait for the beginning of the spring.
But unfortunately it will be a considerable time until this plant becomes a bonsai. Years, probably.

Why keep it inside? Firethorn grows out side here, where temperatures drop below freezing, and they pretty much have to have a dormant period.

Hello. Thanks for reply. I'm from Dublin, winter's are not that cold here, but sometimes can be -5 -7 in Celsius. That's why i'm afraid to keep her outside. Yes she is a very young plant but its ok. I will try to find her a better place outside. Is the pot enough to keep it alive until the spring come?

Nothing wrong with the pot but it must be outside. -7C is nothing for this species

m5eaygeoff wrote: Nothing wrong with the pot but it must be outside. -7C is nothing for this species

Nor is +39C.
Mine are thriving here basking in the summer sun.

Thanks guys for the help. I will let her outside with my azaleas. And next spring will repot and do some pruning.