I’ll be canning for the 1st time in a small camper with very little hot water pressure and Ihave one question.

I'll be peeling potatoes, carrots and onions. I have frozen stew meat too but I want to try the veggies first in case I mess up. The woman in the video (https://youtu.be/DyTQMVyIfjU?si=A5Xx3x9UQCts1E6a, its actually one of my favorite canning videos) says not to keep the lids in a hot water pot, but that the jars and lids still need to still be warm from cleaning them. But then after lightly packing everything down to a one inch space on top, she pours hoy water to the line from her preheated teapot (I bought an electric one) to match the preheated water in the canner. I guess my question is, if I let the preheated water sit for 20 seconds or so inside the jars before tightening them then letting the lids heat up for another 30 seconds or so, wouldn't that suffice? The water I'll be washing all the dishes with will be luke-warm at best.

I'm also wondering if the jars and lids need to be washed if they are brand new.