Congrats! You're sending (and receiving) them now!
If you just want to send a packet, you could use "ping".
ping
www.att.net
Ping will time how long the round trip is from you to the destination.
This command will work in Windows and DOS.
If you want to construct your own packets, there are several programs that will do this for you.
I'm guessing that an empty packet is just like it sounds - a packet with no data... I suppose it should be clarified further, because by definition, no packet can truly be "empty"... But maybe you should find out what a packet is and how it worls before trying to construct them.
Please post back if you have any more questions.