How to use the Segwit and what is the deffernce with segwit2x
The posters above already detailed how to get a Segwit address. This is just about the most concise explanation you can get on the matter:
You can download
Electrum, and once launched it will prompt you to either create a "Standard" or "Segwit" wallet, choose segwit, and voila, there you have it.
What do I need to do?
Other then generating the wallet, nothing.
Segwit2x was a controversial planned hard fork that didn't come to fruition because of lack of support. It aimed to combine Segwit with a block size increase. There was another Segwit2x project that was launched recently if I remember correctly, but it has nothing to do with the original. Neither of them has anything to do with Bitcoin.