Need separate isolated network for work purposes

Hello,

I am currently renting a house that includes Telus Internet, I have to setup a separate isolated network to be able to work as they require this.

I have limited access to the modem it is in Garage but can access if absolute needed I do have access to the login page for both Telus devices it is a newer building and has one cat cable running up to the Apt which is in the 10g port going to a managed switch then switch to Telus Router and switch to my Router/Routers

can someone please help me set up this sep network please I realize this is mentioned a lot but not my actual situation.

I need to return to work from home. 
 
equipmemt 

NH20A

Netgear Managed switch

Telus wifi 7 router 

I have available M18 Dlink, Linksys EA6100,Tp Link deco m4 Router
The Way I had it at last place was put into bridge mode plugged router into port 1 but it is very hard for me to run another cable besides the one coming into my apt.