What lowest dose is lowest to start on with side effects in mind? (tirz)

I’ve had a rough time on the wegovy pill. I decided it bc just lifestyle made it make sense to have bad sides for a day but not for a week on a shot. but I am getting awful awful insomnia and I am gonna to try tirz

my friend said .15 is good starting dose and then moving up from there. does that sound right? I know it’s super low but trying to keep in mind cant afford any more lack of sleep or anything with taking care of a toddler