Daniel,
I can help.
I would recommend you look at BASS project - easier than VSpec and very capable.
https://uk.groups.yahoo.com/neo/groups/astrobodger/info
Sirius (A1v) should show similar features to Vega (A0v), easily identifiable hydrogen lines.
Email me a copy of your raw spectral image, or upload here a bmp version.
You'll soon get the hang of it.
Ken