First raise sitting in a checking account

Been building my startup as a side project and not too long ago we got our first outside money in. Since then the cash has just been sitting in a business checking account and I have been too heads down on the product to think about what to actually do with it.

I spoke to another founder friend of mine who had a situation like this one for almost a year before someone pointed out he was leaving money on the table. He told me that he had assumed a checking account was the default and never questioned it until someone in his network brought it up and it didn't help me in any way which is the reason I came here to get the opinions of other people who have side projects like mine.