The cancellers are not needed for the Camry. You can return those. The harness is up to you if you want to use it. For the 55w kit, I would highly recommend it. For the 35w kit, it's personal preference, but it'd probably be better down the road as without the harness, it may melt the wires eventually.
Here is an h11 install guide on DDM. DDM's support website is a pain in the butt, so it may bring up a white page. The kit is generally plug and play though.
https://www.ddmtuning.com/support/in...mid=14&nav=0,1