Running a digital Game
Digital Table Top
Roll20 is my go to for a digital substitute for a table top. The site itself has a calendar (which from the picture you can tell I am terrible at using) to schedule games with your players and it allows you to add topics in the games to keep notes or make announcements.
The main reason I use Roll20 is for the maps. The DM can hide things from player and pop it up in the screen when needed. Players can move their tokens just like minis on a physical map. There is also the ability to use the measuring tool so players can figure out how far away they are from creatures, can figure out movement, etc. with the simple click of a button if they don't want to count the squares on the map. I love that images and maps can be easily uploaded. It is a great tool for DM's to add visuals for the players.
There is a chat bar on the side of the screen which I use for players to record their initiatives and rolls for reference. Players can use this also to write notes if they wish or for DM's to place names of NPCs or places.
I also love that there is a marketplace where you can buy resources for your games from books, to complete adventures, map packs, animated spells and more. Roll20 has things from Wizards of the Coast, Paizo, Chaosium and other major publishers. With a little bit of patience and a some imagination any table top game could be played on Roll20.
Some of my gaming groups also use the voice/video feature that Roll20 offers to communicate while we're gaming instead of discord. You are able to do characters sheets on Roll20 but I personally have my players use D&D Beyond.
D&D Beyond
I personally have my players use D&D Beyond for their character sheets. Not only does D&D Beyond have a lot of good resources for new players learning the system it is a great tool for DM's and players alike.
All of my players are asked to make their character sheet using D&D Beyond and have them added to my campaign. I am able to see my players sheets, players are able to use the digital dice if they choose, and there are tons of links and pop up information that is needed to help make a player successfully run their character smoothly.
I wrote an entire article on D&D Beyond that can be read here if you want more information.
5th Edition Rules
There are a lot of links and online tools that I send my players to for references. Something that is always open on a tab for reference is Crobi’s quick reference guide found here: https://crobi.github.io/dnd5e-quickref/preview/quickref.html.This has a very easy to use guide of what players can do for movements, actions, bonus actions and reactions. There are also details on common conditions and environmental effects. What I love is each image can be clicked on for more details and there are page references for the Players Handbook.
World Maps
I use Faerun as the setting for many of my campaigns and a lot of official adventure modules are also set in the world of Faerun. I send my players to Lore Maps by Azure Websites for referencing. Why I love this site so much is the more well known locations have blue markers that you can click on for more information. There is also the ability to hex the map to better tell distances and you can click to see how far places are when the party is trying to map out how they want to travel.
Digital Dice
There are a few ways to roll dice if you don’t have physical dice. Most of my players use the dice that is available on D&D Beyond or their physical dice. However there are other options for dice such as Wizards.com or apps on phone devices. One online options that I like is Brock Jones. I prefer Brock Jones because it does seem to be random and unbiased. I also love the ability to roll for Character Stats using this link and it gives you different options to use such as 3d6 strict or my go to, 4d6 drop lowest. Always consult your DM before rolling stats to see what they prefer.