I am fairly new to the quilting by machine part of quilting, too...I found great videos on youtube, started with some smaller projects, have taken out countless stitches :-), and finally feel that I am getting it..biggest I have done so far is a full size quilt. I also only spray baste, and only use 505 to do it..there is a great vid on youtube about that, too...it is in with a 4 step tutorial on free motion quilting. If you can, watch all of the steps, they are very helpful! In my opinion, stitch in the ditch (or rather about 1/8" away) is easier than the free motion...I have done it several times, and rarely have to take out stitches on it...I have used both a walking foot (even feed foot) and just my regular foot..If I use batting such as warm and natural, and spray baste, then my regular foot actually works better than the walking foot...for me, anyways... I can see where you would like to see the quilt through to its completion...so, as the others have said, practice, practice, check out youtube vids, do a few smaller projects first, like on a preprinted quilt panel, etc...and, I also got on Amazon and bought several great books on machine quilting...
Good luck to you!
K