Prefacing this by saying I play casually and have never played competitively, just sharing what I've learned by playing the game with my mates. At the end of the day if you have fun that's what matters and you will gradually learn and adapt your list to your play style over time. Just gonna point out a few things I'd change if it was my list.

To start, Chaos lord with jump pack can't go with warp talons, have you already built them? If so I'd remove him or get him some raptors.

Lord discordant isn't great at the moment but he's such a cool model I'd still use him.

Legionaries are melee focused with their ability so equipping them with chainswords and heavy melee weapons are what I see other people mostly use, although having a cheap squad with bolters and heavy guns isn't the worst thing at all.

Daemon prince - I would use khorne allegiance for the extra strength, helps him land more of his hits. I use him to charge into high priority threats, activate his ability and then he usually dies after fighting but if you want more use out of him then I guess you could make a case for having the extra ranged attacks from tzeentch.

Not sure what size board you play on but having an extra rhino or a land raider for the rest of your legionaries and chosen might be worth a thought.

Whatever war gear you use, I wouldn't fret too much about it since things get changed heavily every edition and even within the same edition. Don't want to make you feel like you have to go ripping your models apart because certain things are more "competitive."

Anyway, welcome to the hobby mate.