Finding simple ones is a bit more reliant on your judgement. I guess you could possibly google something like ‘simple lego sets’ but I’m not sure it will bring much up. You also want to look for ones with fewer pieces.
Try things from this list (all of them are doable):
8678 - Francesco from Cars 2
42031 - Cherry picker (There is an A and B model so you can pick which you want to do)
8641 to 8642 - These are just some little cars (if you choose to do these you will see in the instructions there seems to be half of another vehicle, that’s because 8641 and 8642 make one big vehicle and 8643 and 8644 make another big vehicle).
40086 - Rabbit
If you want to sit at your computer for several hours then you can try 42039. I’ve built this one physically but not on LDD.
EDIT:
This is what they would look like: