I be been keeping my dream journal for a while, and it’s helped me increase vividness. I have achieved lucidity before, but I want to find my dream signs to make it easier. All of my dreams seem to be all jumbled up and random, and share almost nothing in common. The only thing I can really find is that people are always in places they shouldn’t be, such as my friends from other schools at my school, etc. any tips on finding dream signs?
Well, you already found one dream sign - people being in places they shouldn’t be. 
You can use that, but there are induction techniques that you can use that don’t involve dream signs. You can do RCs outside of dream signs, and MILD and WILD don’t require dream signs either.
Yeah, I already use RCs and induction techniques, and they’ve been pretty successful, I just want to find dream signs to raise my chances of a DILD
Just do RC’s throughout the day and they should appear in your dreams sooner or later. If there are no dreamsigns, just do them whenever you remember to, or practice Lucid Living.