I need to enable billing but how do I setup the quotas so that I won't get heart attack?

I am using VertexAI with gemini-2.0-flash and text-embedding-005. However, I don’t see these in the Dimensions column in the Quotas and System Limits page of gcloud console.

How can I setup the billing with caution so that I don’t get heart attack at the end of the month looking at my credit card bill? I am only using the API for development and testing purposes with LangChain/Graph. Nothing serious. Any free credits for us to do technology evaluation?