Hi,
Don´t be afraid.
As long as you keep on the datasheet and application notes you are on the safe side.
The manufacturer provide these documents to ensure the customer is satisfied.
If you expect some more detailed answers then we surely need more informations.
The only thing we know is the battery.
But to find asuitable device one needs to know a lot of parameters. Like load current range, charging current range, timing, accuracy, and so on.
Usually selection tools ask for those informations. No one of us can give you these informations.
And the application notes tell you what to care for how to calculate some values...
Klaus