Donna

I would start by making this a very special happening by slipping a colorful invitation in a sealed envelope, under the doors of some of the residents; in the invitation I would make sure they understood this involved a big secret .... they cannot tell anyone about this special invitation. You carry on this theme of "special", "secret" by writing something like "Murray look inside ONLY if you feel extra brave today." Inside the envelop would be the invitation AND a safety pin through a colored ribbon with the instructions to pin that ribbon on the collar of whatever they are wearing tomorrow. Also let them know in the invitation that he/she will be called for a special event at 2:00 o'clock or whatever.... If you set the time for any time other than the normal activities time, you will create even more suspense. This will build up the suspense.
As for picking those clients for the very first day, I would suggest... - if some of your clients always hang out together, send an invitation to only one of a trio; - make sure your list includes the leader of the pack at large.... especially if that leader is a negative force to most things. And so on.
You can make the walking (of the chosen ones) as secret as you like by whispering, not allowing doors to slam... In an ideal world you will lead this group to a room that is not your activity room... maybe someone's office. There you can run it however you decide.... are you asking the chosen ones to help you with some task (organizing a Hallow'en event), help you to run a survey (to find out so and so's hobby, birthday); to pick/ vote in the ones (only 2 people, maybe 6) who will join the chosen ones the next special day; to create a special card for the new Prime Minister etc.; to be prepared to go to a matinee tomorrow or the next day/week.. (Do they want to keep the activity of the matinee a secret?) Post this special event on a calendar in the activities room. Most theater managers will support you if a group picture can be taken for the local newspaper or to hang in the lobby. You could discuss how everyone will want to have their jackets and street shoes ready and you might want to pick Mary to be a partner with X.... for safety sake. This group of the chosen few may want to keep this as a secret club for the next week or two, they may decide to keep the matinee a secret... whatever.
All to make this a very SPECIAL thing to be part of.
And you are off to a good start....

Some web-sites to look at as a resource is Alzheimer'sSociety.com, BCAlzheimersSociety.com; I know you are looking for dementia resources' not just Alzheimers, but those sites are for dementia (not just Alzheimers). They support you by giving you more information about how to work with a difficult client, other things to expect and different ways to handle the situation. They are great in mailing you prepared literature on various topic.
Other web sites I would look into are those of companies that provide education / skills for those entering the careers of Home Care. Here is one popular site PAID TRAINING - Home Support Worker
CarePartners - Owen Sound, ON
SUMMARY:
CarePartners is offering a PAID opportunity to receive training and skills needed to work as a Regular Part-Time Home Support Worker (HSW).

Training begins November 12th, 2019 in Owen Sound,ON. and includes:

PAID in-class education with a Nurse instructor
PAID job shadowing with a Personal Support Worker Preceptor
3 days of PAID company orientation

WHY CHOOSE CAREPARTNERS:
Paid KMs PLUS travel time
Uniform Allowance
Mobile Device
Comprehensive benefits package
Employee Assistance Program

RESPONSIBILITIES:
CarePartners HSWs provide professional, compassionate care in homes and residences in the community. HSWs assist with activities of daily living, allowing patients and families to live life to the fullest with dignity and independence:

Bathing, showering, personal hygiene
Bowel/bladder care
Dressing
Meal preparation
Transferring/repositioning
Light housekeeping
Socializing and companionship
CarePartners welcomes and encourages applicants from people with disabilities, accommodations are available on request for candidates taking part in all aspects of the hiring process.
Under the circumstances I believe CarePartners would mail you a more detailed copy of their lesson plans etc.
You have a lot of courage venturing into this.