Hey. I'm a Teacher of the Deaf so some knowledge of audiograms!
So, very basically, they play different beeps at different pitches (tones) and they play them at different volumes (decibels - db). So the lower pitch tones are 500Hz and the higher pitch tones are the 4kHz or 8kHz.
The numbers 0, 10, 20, 30 etc. are the decibels, so the volume the tones were played at. A person with normal hearing will hear the tones at a quieter volume, so the lower decibels numbers (0-20dB ish). The more your hearing loss, the louder the tones have to be played for you to hear them, so for people with a hearing loss the dB numbers will be much greater.
So, it looks like you could hear the lower pitched tones (1kHz) at 25dB, so not much above normal. The slightly higher pitch tone (2kHz) was 30dB, so indicates a mild loss. And the high-pitch tone at 6kHz had to be played at 45dB for you to hear it, which would be a mild-moderate loss.
However, please remember that online audiograms are definitely not scientific! So tomorrow is important to establish exactly what hearing loss you have. It looks as though you will probably have some high-frequency loss, but whether that's one or both ears remains to be seen.
The audiologist tomorrow will run a similar test, but they'll check your ear pressure and how clear the ears are before testing each ear separately, with tones and possibly mask the other ear with white noise (ears are good at helping each other!). They may also test the bone conductivity, which just means they'll show you how sound can travel using the bones in your skull! (It's painless and my fave test - just requires a different headset is all!)
Good luck tomorrow, but you'll be fine! Let us know how you get on!