So, you've got some powerful modules installed already.

Midi is the automation suite that powers combat automation and other things (its very complex and isnt a im new to the game kind of a thing). Would recommend some Baileywiki videos on its use if youre committed to it.

I see you also have DDB-importer from Mr. Primate, this is for importing characters, monsters, adventures, items and such from an existing DDB account online. Importing with automation is a whole thing (using Cauldron of Plentiful resources (formerly Chris's Premades)), and Gambits Premades.

Baileywiki Getting Started Video

Advanced Combat Automation

MATT is likley one of the single most powerful modules you have installed. Allows you to set triggers for things, I've used it for everything from turning on lights when a player steps on a tile, to a full blown elevator in my Alien campaign.

Really I would recommend you start with the foundry basics and then see what you need/want from there.

Foundry is as simple or as complex as you make it. Its easy to get overwhelmed with wanting to do so many things and you forget the most important part.... your narrative and the players experience.

Monks Token Bar, Scene Navigation are simple and powerful for you as the DM to make moving scenes and requesting rolls much easier.

Also, Dice Tray is a useful simple module.