I signed up with a financial advisor but now I changed my mind.I have not given advisor any money yet.they are now calling me so I can give them the check which is for 300,000.I did not do my homework and was referred by friends because I know nothing about investing but I just don't feel right about giving it to them.they have opened me a account also.what will happen if I do not give them money and what should I tell them.. I feel so stupid for doing this and I'm a nervous wreck!

You need to read the contract you signed with them, It may have a time frame you can cancel.