Hi!
I'm a new DASH user

I saw the presentation by amanda at anarchapulco and it really was looking nice!
Instant transactions, private transactions, a return on your savings. Also the vault seems a cool system to protect my money.
I have some questions:
1) Will it be safe to use my account on a lot of devices as long as my money is in the vault ?
2) I bought 380 DASH. It's a lot of money for me, but I don't want to miss this opportunity !!
I bought at 34 USD, so I already have a nice profit

It's still on poloniex, but can someone tell me how to get the savings account?
I hope I'm not too late to the party and dash will continue to go up

Thanks amanda for opening my eyes to this wonderful opportunity !!
What Amanda was showing was a preview of the upcoming Dash Evolution update, which is scheduled for end 2017.
The savingsaccount and the mentioned vault are part of that upcoming Dash Evolution update.
At this point you are better served with downloading an official Dash wallet from dash.org
encrypting it with a good password, transferring your funds from the exchange to your local wallet and making plenty of backups and keeping those backups offline (encrypted USB stick or encrypted external drive offline).
Make sure your computer is clean as well, make good use of anti-virus and anti-malware programs to scan you computer.