Hello Miss Gunjan Aggarwal, Thanks for the compliment.
MongoDB has a program called the AI accelerator; https://www.mongodb.com/services/consulting/ai-accelerator
that will be helpful to your startup. For the cloud service; MongoDB supports both AWS and GCP.
The choice should be be up to your technical team, my inclination(not a suggestion) would be AWS.
I have a strong recommendation (design with security in mind for the software you are building) Against prompt injections and all sorts of AI security loopholes that make you prone to attacks.
I hope these answer your questions satisfactorily