Welcome back Scott !
2 years is quite a while, so first thing is the
batteries.
Did you keep an eye on them in storage ?
Ie check / charge now and then if voltage got low-ish, like 1 bar flashing.
Do they still show a discharge state with one push ?
Do they behave normally on the charger ?
They've possibly survived the long period of non use without 'bricking', assuming so . . .
Check all this at home, props off on a table is safest.
Install fully charged
battery.
Connect up controller and new device (compatible I guess ?) . . . I've always used a cable connection, but you might use wifi ?
Some say there's a particular order to start / connect everything, but I've never had an issue starting whatever first.
When Spark is activated (short then immediate longer push), just wait for signal connection and controller view.
Check all features of the Go4 app, gimbal movement, try a photo / video with it sitting on the table.
Check
battery especially, the cell balances to ensure all even, do this with all your
batteries.
If all appears normal, take it outside and check / fit props, give it some safe short test flights in a large open flat space (sports oval / park etc).
Experiment from there, taking further / higher flights until you are happy with things being normal, hone up your stick use etc.
Enjoy ! (Again)