What should I do if my admission letter doesn't say anything about funding? I have received my admission letter for a graduate program. But there isn't any information about funding. I have talked to my professor about the availability of funding. what should I say to my professor?
It is very common that an admission letter itself doesn't contain any information about funding. However, it is assumed (at least in the US) that information about funding will be made available to you well before you have to give an accept/decline decision. This often comes in a separate letter/email, sometimes within 1 day of the first letter, and sometimes more than a week after - all depends on the University processes and timelines.

Regardless, it is perfectly acceptable to contact (call or email) the University to inquire about funding offer timelines. Usually you would ask the graduate program administrator, and they can answer or direct you to who you should contact instead. It's fine to ask the professor, but they might not know and thus haven't answered (they may very well have seen your email and sent off an email of their own and are awaiting a proper answer). Funding in academia is often weirdly complicated, and often requires multiple calls and emails to multiple people to figure out all the exact details. Often this process is made invisible to the student.

If you've had silence from all channels for over a week - or if there is some very pressing deadline approaching for you - you should re-attempt contact and politely inform them of the deadline you are under, and your need to hear about funding prior to that time.

As to what to say to your professor, if you haven't contact them already, it's usually safe to confirm you received your offer of admission, say thanks and express that you were excited/glad/pleased to receive it, and note it didn't mention funding. Then just ask about the status of funding available for you - and that's pretty much it. 

Congratulations on your offer of admission, and good luck!