Help with starting up

I have an archon right now. Thats it.

I'm making a trade (hopefully) with someone online to get 20 kabalite warriors, and a raider (maybe on the raider he never said)

Once I have these warriors (assuming I don't get the raider) I have a choice from another person, I can either buy 2 raiders, or 1 raider and a box of wyches.

I can build 500pt lists out of either buy, that's not my concern.
My concern is, which route would be better in a 500 pt army?

I would suggest the single Raider and wyches. That would give you more flexibility in building small lists. The lack of mobility will be a concern, but I start most of my units outside their vehicles now and they do fine. Your next step after this might want to be a Venom, if possible.

Cheers.

although the more transports you have, the better...

I would get the two raiders, as you can always buy a battleforce later and get those wyches (as well as another unit of warriors and another raider...)

i started my army quick by buying 2 battleforces and 6 venoms and an archon. it wasnt cheap though.

I'd say it depends on how good a deal you are getting!

But if you are going purely on playability it is better to have troops and no transport for them than transport and no troops to go in them - so it may depend if you get that first Raider or not.

Either way enjoy your first DE!