Thanks.
Still kinda confused how I will end up with 2 lots of coins when I have one wallet and one set of keys...
Well, that's the worst case scenario with a fork, they never come back together and the two chains effectively become two incompatible cryptocoins. In this hypothetical scenario, the two coins share a history up to a certain point at which they diverged. You have private key(s) which are from the shared part of the history. That means that just as one cryptocurrency has now become two, your coins in the original cryptocurrency have now become coins in LeftForkCoin and in RightForkCoin (I love these names). As long as you control your own private keys, you are safely a part of the "winning" coin when and if a "winner" becomes apparent. If there never ends up being a winner and both forks retain their value, you're happy to have both coins.
I hope that helps.
So what if LeftForkCoin and in RightForkCoin really happens after that SegWit2 will be enabled, Should I really make a hardware wallet early as now and get my bitcoin balances from Coinbase? or this Online wallets have a plan also with this event if it will really happen? I am not a geek to know about this sorry.
You have to go by what the wallet providers publish. Trezor is on top of this and is in stock, recommend you buy one before they run out. They seem to be selling fast:) Ledger is already out of stock.