Just get the resin mix and enough fabric to make a skid plate on the bottom. Make your patch for the hole bigger than the hole itself. You might want to patch inside and outside. What you do is sand well around the areas you want to repair and apply some of the fiberglass resin and put the fabric on and apply more resin. You may need a few coats of resin or a couple of patchs depending on the damaged area. I got a canoe that had holes in it at a yard sale for $25 and got the resin mix and fabric and patched it this way and it is still good today. Go to youtube and maybe you can get a video on canoe repair. Pretty easy to do. Resin comes in two containers like a resin and a hardner that you have to mix together. By the way canoe is great. It is an old Sawyer and haven't used it much but no leaks and it is an awsome canoe.
If they aren't big holes you can use those marine epoxy sticks made by JB Weld, Devcon, Loctite,etc. You slice off a piece, and knead it till hot and press into holes. You can sand and paint after it dries. You can buy them most anywhere. They work underwater and good to carry for emergencies.
Using a canvas covered wood canoe I can tell you that Duct tape is your emergency on the water friend.
Fiber Glass can be built up w/ fiber glass mat in the deeper spots and then covered w/ fiber glass cloth layers for a uniform surface.
After sanding if you have any small imperfections don't grab bondo; visit an auto body supply shop for a tube of 3M spot and glazing putty and apply it in thin layers. I used it to 'fill' bad spots in the canvas filler when I re-did my Old Town in 2001. The stuff adheres well, sands real smooth and is still holding fast today. I paid $12 - $14 a tube in 2001.
Make sure you wet out the glass mat real good and push out any air bubbles because they will rub through...uscomposites.com is a great source for resin and glass mat...epoxy resin is alittle more pricey than the fiberglass but much stronger if your dragging the canoe around alot...don't use the flex seal from tv it will peel off in sheets