Hi Steve, welcome to the smokin'it family! On the seasoning run, use two dowels of the hickory that will come with the #2, set the temp for 250F, and let it run for 3-4 hours, probably closer to 4. You don't need to foil the inside for the seasoning session. You will see a lot of smoke within the first hour, and then the smoke will taper off, but let it go for 4 hours to completely consume the wood.
You will find with these smokers that you only need a small amount of wood to get good smoke taste ... often as little as 3-4oz of wood. If you have a small kitchen scale, this will help to make weigh the wood. I only use the catch pan that does under the smoker when smoking. When smoking meat, you will want to put foil over the top of the smoke box and on the floor of the smoker (this helps in the clean up phase!). Be sure to punch a little hole in the foil on the bottom where the drippings can run out of the bottom of the smoker in the catch pan.
I see no reason why you would not want to use pieces of wood from your apple tree, although I have not heard of using plum for smoking. I saved parts of a cherry tree that was pruned a few years ago and use that wood for smoking.
I have been using my #2 for 1.5 years now and love it ... you will be amazed at how easy they are to operate...literally set it and forget it! I would, however, recommend getting a remote thermometer to monitor the temp of the smoker and the IT of the meat that you are smoking. I have the Maverick model that has worked well.
Finally, take some time to look around in the forum boards...lots of good advice, recipes, rubs, etc. Post questions any time! Cheers.