It is not an assistant, you CAN use it as an organizational tool. If that is all you want. I would advise taking a look at some of the YT videos on what it can do. Or download the demo from the store and play around with it. The demo is fully functional except saving.
https://www.youtube.com/watch?v=UemN5_WY7rE&t=1217s
https://www.youtube.com/watch?v=NbPUYxLKw8A&t=0s

The wiki is also a good resource for info, specifically the managing campaign data section.
https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/996640868/Managing+Campaign+Data

I started DM with paper but saw this after some weeks and started learning the app (youtube guy, probably the one the guy above is showing you), and man, this will help you a lot, from fights, remember stuff, and you can buy the books from the app with lots of automations that will make you life easy for DMing... I mix with paper too, because my friends like using the stuff and see on a table, but for me, I keep the laptop as the DM area so they cant see... and if I want to show some stuff, I show on the tv for them.

If you're just using it as an organizational tool, it's pretty robust. Manual data integration is a little obtuse at times, and the baked-in map editor is pretty meh, but once you start building your "canon" of rules and data it's probably one of the best tools out there (assuming you get an ultimate license). Just get a better VTT-capable map editor like Dungeondraft that can output VTT2 files and import them into FG instead of using the baked-in mapper.

For visualization and actual session play, it really depends on the ruleset you're using. If you're playing PF2 or D&D 1/2/5E, you're good. But if you're playing an obscure ruleset that hasn't been licensed or are a 3E/3.5 holdout you're going to have a lot of personal adaptation and extension installation to do and it will take a long time before the platform is worth more than a personal notebook in terms of organization.

Actual coding is mostly important if you want to implement game mechanics which haven't already been added, whether by Smiteworks themselves or via third-party extension (plenty on the Forge).

Reference manuals, tables, maps, NPC sheets, item records, spell records, encounter records, parcel records, character sheets... there's a lot of ways to organize data and a lot can be linked to each other (e.g. book entries linked to an encounter record which will link to NPC records as well as to the placements of those NPCs on a map, and also linking the book entry to a parcel record specifying what might be found, w/ links to item records). Depending on the ruleset and extensions in use, stuff like item records might be linked to spells or activities, might have sections for a GM to keep only-visible-to-GM notes on them, etc.

Extensions can provide a lot of useful features such as being able to place shareable pins on a map (e.g. marking and labeling points of interest that the party would know about). One extension that might be of particular interest is called "Player Agency" ( https://forge.fantasygrounds.com/shop/items/511/view ), mostly for its World Builder ( https://www.youtube.com/watch?v=7yQtfKf2yD4 ) and Investigator ( https://www.youtube.com/watch?v=ToZDZJBBR50 ) components.

I highly recommend you load the built-in Tutorial 5E Campaign and walk through that even if you don't plan on playing D&D 5th edition. It will teach you a lot of the core principles very quickly and you can apply those to pretty much any game system (which we call rulesets) that you decide to play.

Unless you are young and or adept at transfer this and that create this or that....you might have issues like I did. After 5 hours I gave up trying to figure out 2.0 D and D.