How can i assign the values of keys in different variables so that i can use these variables in different part of my program?

I'm not going to do that as I think it's a bad idea and that keeping the values in a single hash is easier to code, more flexible and more maintainable. You have all the data in a hash. What can you gain from copying it into separate variables?

If you really want to do this, then you should look for information about "symbolic references". But I really don't think it's a good idea.