How to practise these Nuke lineups
Start a private match on Nuke (offline with bots, or your own server), open the developer console and enter sv_cheats 1. Then copy a lineup's line and paste it into the console: setpos puts you on Valve's throw spot and setang turns you to face the aim point, so all that is left is the throw itself.
These are Valve's official lineups in CS2: the positions, angles and instructions come straight from the grenade guides the game ships for Nuke, not from community guides. The names of the places they land on are on the Nuke callouts map.
Lineups for other maps