If you got with an inverter get a “pure sinewave” model.
What else do you need to power, I’m guessing your setting up a small
sound system of some sort.
If that’s the case the power requirements for the mixer are not
going to be the issue.
The power draw/requirements for amps and or powered speakers varies depending
on how hard there being driven, as in how loud it is.
Music or for that matter just amplifying voice for announcements can have
peaks that require brief moments of higher power draw, if the power inverter can’t
keep up your speakers will start to sound or shut down from the voltage drop or the inverter will trip a breaker/blow a fuse or just shut down.
As XYZ mentioned the Honda inveter generators are great, very quite and come in various
sizes, Yamaha also has some.
Some tool rental shops have them available.