You can research this online, but you need to do a hardness test, a streak test, a specific gravity test, and maybe a cleavage test (this has to do with how the rock breaks), posting the results of these tests will greatly narrow down the possibilities of what this rock is.
The first two test are very easy to do, the hardness test involves trying to scratch the rock starting with something like your fingernail and progressively harder items until one scratches the rock.
The streak test is rubbing the rock on a "streak plate" which is a piece of unglazed ceramic material and noting the color of the streak, there are many streak color charts online, the under side of a coffee cup or the underside of the toilet tank lid will work for a "streak plate" sometimes it's maybe necessary to have a dark colored streak plate for some lighter colored minerals/rocks, you can also buy inexpensive test kits if you chose that has what you need.
The specific gravity test takes following instructions, a digital scale, and a little bit on doable construction to suspend the rock while weighting it.
The cleavage test involves learning to identify the type of cleavage when the the rock breaks.
