it took us 13 hours to get down a 5 track very rough demo recording as if live, no punch ins, and only had to redo one song. you are doing each track individually it seems like. i assume your songs are around 3 minutes long, so recording a song, no screw ups will take you 12 minutes with the tape turned on, and 15 if your dad is playing guitar. that means you can do 4-5 songs per hour in a perfect world (i would shoot for more like 2 or 3 per hour. i would say you spend at least 1 hour per song mixing and editing, but if you can sacrifice quality, you can probably do less. this really seems like you should be doing 4 to 6 good quality songs IMHO. professionals (this does vary a lot) will in general spend 30+ hours in the studio recording 8 and 9 track records, only using around 8 hours for tracking, then time in editing for punch-ins. so almost double the amount of songs in 1/5th of the time just seems completely impossible.
you said you wanted to record a demo, and in all seriousness, managers and talent buyers usually will not give you the time of day if you are self promoting, and if they are interested, they are "busy" and will only listen to 1 or 2 tracks. i am doing all of our promotion for my band, and this is from experience. i used to have 10 tracks on our press kit, from both studio and live sessions, and then took all but 4 live tracks down, and this has not affected us getting gigs in any way.
that said, have fun in the studio it is a great time (your first time at least) and you will probably learn alot, about the business and your playing. this post might seem a little harsh, but you need to see how much work goes into a record, and if you went in expecting to do that many songs, you would probably be crushed when you ended up with less than half of what you expected.