First get your Sound levels adjusted “in the ballpark” for your sound card interface to the radio using Fldigi! Then you can be successful operating packet.
“Packet radio operates on the 2 Meters band or Very High Frequency (VHF) at a 145.05 MHz, , 144.91 MHz & 144.93 MHz frequencies, and are similar to the internet, but primarily text and at a much slower transfer rate of 1200 baud.” (From BARK packet page) Berryessa Amateur Radio Klub also has a Facebook page.
There is an active packet radio group in the Sacramento Valley and a network of Digipeaters called K-net.
It is not necessary to use a hardware TNC anymore to operate packet. A program running as a virtual TNC and a sound card interface to your radio will suffice.
Then you also need a terminal program to operate packet radio on your desktop. a good simple one is found further down on The UZ7HO page (easyterm39.zip.
Stands for Automatic Packet Reporting System. Yes it reports position, but a whole lot more!
APRS with UZ7HO Soundmodem