Money is automatically split evenly between group/raid members.
If the amount cannot be split evenly, the looter gets 1 copper extra which is a very marginal amount.

If you don't have a higher level on the server to assist you financially, it can be very hard.
I'd suggest having mining and herbalism on your most active main screen. Mainly because you cannot macro these.
Have skinning on one of your alts with the 2 line macro, "/targetlastenemy" and "/use skinning(apprentice)". Change the macro to your skinning skill as it appears in the spell/ability book. (P).
Enchanting on one member of your team. It will cost a little to level up at times, but being able to disenchant instance/quest rewards for sellable enchanting ingredients will pay off down the road.

The lowest alliance instance is deadmines, which is geared towards upper teens or lower 20's characters.
It's based out of the town Moonbrook, in the southern edge of Westfall which is the second human zone from Stormwind, after Elwynn Forest.

Cloth looted can be sold, you'll get a lot more on the auction house then you will from a vendor.
Set of an auction house toon, which lives between the mail box and the auction house.
Auction cloth, herbs, skins, disenchanted items and mined resources.

Your dps toons can be somewhat undergeared and only really need their most commonly used dps spells.
Your healer should have the maximum rank of their heals spells.
Your tank should have the best gear you can get for them along with their tanking abilities at current level; this toon will be the cornerstone of your team.
I'd not buy any/much gear on the auction house, as quest rewards and/or instance drops will be enough to level you.
Be frugal, its hard with a team on a server without higher toons.