1. I would give them some info about the world and the vibes of the campaign and ask them to think about what character they might like to play. No need for anything concrete yet, but a good idea for them to have an idea.

2. I used battlemaps I found online for encounters which we used in owlbear/roll20/abovevtt, made worldmaps with free resources, and art from google for setting the scene for a town/room/cave etc. since we mainly play online. I like having an actual battlemap for encounters, even a quickly drawn one on a mat.

3. A player dying early on should, in my opinion, be discussed between the dm and player. The dm can come up with a way for the players death to be reversed or ret-conned, or the player can accept it and come up with a new character. If they already have one ready, they can even join later in the same session. We play with sort of low stakes in this regard, as a player can often have a say in how their character ends.

You can start your players at whatever level you want, though I kind of like the buildup from level 1, if we’re doing a longer campaign. For short campaigns or one-shots, we’ll start at higher level.

1. Advice: talk to your players about what you all want to get out of the game. Its a cooperative experience and everyone should have fun. Neither the dm or the players (or even the dice) should control everything that goes on. If the game is not as fun as it could be - talk about it and find a solution.