Hello
Also keep in mind that to secure completely your NXT account
you need to send out at least one transaction which could be send a some coins
form your account or register an alias name.
Also when registering NXT account choose a pass phrase wisely
at least 30 characters including all possible chars like #$%&0 etc..
Your pass phrase is your account and if you forget it you are fucked so write it down
somewhere on paper.
Good luck.
Great advice! Thanks

NXT uses a brain wallet, so you MUST have a long random pass phrase with uppercase, lowercase and other characters.
As freigeist mentioned, you need to make an outgoing transaction to give your account a public key which ensures maximum cryptographic protection (256 bit rather than 64 bit). Register an alias, or send a message, or send to another account.
Please, if you are new to NXT, and do nothing else, do these two things to secure your funds.