Hi there, Theresa!
Thanks for stopping by the Moms Panel with your question!
You can just go right up to the Park entrances with your tickets purchased from Undercover Tourist. You don't have to do anything special with them at all before you use them because they are ready to go.
The new touch point scanners are currently being used for the MagicBand testers as well as for Guests with the plastic RFID cards. The last time I visited the Parks, there was a separate set of turnstyles for Guests using the paper tickets. A Cast Member will definitely point you in the right direction if anything changes before your vacation. Lots of new and exciting changes are going on with the new touch points!
As far as tickets for
Mickey's Not-So-Scary Halloween Party, those must be purchased directly from Disney. You can either purchase them online or in-person at the ticket sales booths at Magic Kingdom Park. My only recommendation here is that if you've got your date picked out, you'll save a few bucks on select dates by pre-ordering. Also, you might not want to take the chance of your ideal date selling out before you purchase your tickets!
I sure hope this helps, Theresa!
Please let us know if we can help with any other questions you have.
Wishing you a Pixie Dusted vacation!
~Jackie