SN1 and E1 have identical rate determining steps (RDS) so they
occur simultaneously and have the same properties.
remember for Sn1/E1 reactions that bond breaking occurs before bond making.
One of the few factors that affects SN1/E1 is when stabilizing carbocation.
there are a lot of helpful videos on youtube.
I hope this helps
Watch these videos.
Here are some more videos that will help you fully understand SN1 and SN2 mechanisms.
Organic Chemistry | Predicting the Mechanism as SN1 or SN2.
Organic Chemistry | SN1 and SN2 Practice Questions - Chiral Molecules.
Organic Chemistry | SN1 and SN2 Practice Questions - Chair Conformation.