If you are serious about spending thousand of dollars then you need to first do "some" homework and then ask some productive questions so that folks here also feel like they are explaining to someone genuinely interested rather than just a rock.

To answer your question - Open an account in bitstamp or coinbase. I use bitstamp. You can buy and trade from there.

Before asking how to create an account there, and on the necessary credentials that they require...I request you to find some information on how bitcoin works - most importantly the trading of bitcoin. There are plenty of online articles and videos on it on many credible news websites.

Then bring your questions here.

Best of luck!