How much work is done for you in this software. Does it have models of furniture that you can edit the sizes on or is it line by line?
Bit of both.
There is an online library of ready-built modules available to add to your design. The library is populated by Sketchup users so it can be a bit random, but that said it is massive so there are all sorts of items. Even if there isn't the exact item that you are looking for there is usually something near enough for visualization purposes.
In my model above, the people, cooker, fridge, microwave, batteries, inverter etc. are all imported.
Sketchup is really quite easy to use but it is definitely worth following an online course to get up to speed quickly. I use Udemy for my business training so enrolled in
https://www.udemy.com/course/master-sketchup/ which is currently on special offer for £9.99
I must say I'm having great fun moving stuff about and playing with my design. Definitely better to do it on the computer rather than in the van!
Regards
Phill