Can I double my money through the upcoming Segwit2x fork?
The "Segwit2x" fork is scheduled to activate at block height 494,784. After this block, there will possibly be 2 independent blockchains that grow independently of each other. If that happens, then any BTC you held before block 494,784, would also be available on the B2X fork. 

This doesn't necessarily mean you would double your money. It's possible, but it depends on how the market prices both BTC and B2X. For example, if you held 10 BTC @ $5000 before the fork, and then the fork happens and exchanges come back online and the market prices BTC at $2000 and B2X at $2000, your 10 BTC + 10 B2X would be worth less than before the fork. It's impossible to know how the markets are going to react to the fork and how messy it's going to get.