What package should i not delete from cydia

[MrChallenger360]

so i just got my iphone unlocked/jailbroken and i've been going through cydia and downloading a whole bunch of mods to make my phone the way i want. however, now my phone is super slow and i don't have enough memory to run a lot of my apps. now i know the packages i really want and i have a ton that i don't need any more. so i'm wondering if i can just go through and uninstall everything that i don't recognize as something i want or if there are system files and stuff i need to make sure not to delete. if someone could at least answer if i need to be careful or not. and if someone could come up with a list of what is necessary and whats not that would be even better

[BlackWolf]

if you don't recognize something, leave it. everything you installed you should recognize one way or another, because if you don't ... why did you install it?

also, look at the category of the package. some categories like themes etc. can be deleted safely