Are they the first human race, and where did they come from?

http://www.uesp.net/wiki/Lore:Redguard

Sorry for my horrific lack of lore-related knowledge, but what is Yokuda?

An ancient city that sunk under the sea. Kinda like if Redguards used to live in Atlantis. It was near Akavir.

http://images.uesp.net/f/f9/Tam-Maps-West_Tamriel.jpg

i sland homeland of the red guards they conquered hammerfell when it started to sink into the see, it no longer exists

actually akavir is to the west of tamreal

Yokuda was a continent to the west of Tamriel.
It was home to the Left-handed Elves and the manish race that became the Redguards.

It was (for the most part) destroyed in terrible wars. The Redguard sword-singers knew how to craft blades capable of splitting the atomos.

The original Yokudans were one of the first mannish races, together with the Nedes and proto-Bretons.
They all come from wandering Ehlnofey.

Can't multiquote on my phone but thanks to all replyers. Really need to touch up on my lore

...And Yokuda is...west...of tamriel....

Just thought I would throw this in there :

"Do not believe the written histories. All life started on the Starry Heart of Dawn's Beauty, Tamriel."

Did you see those warriors from Hammerfell? They had curved swords. Curved. Swords.

sorry i miss typed yokuda is west of tamriel but akavir is east http://www.uesp.net/wiki/Lore:Akavir or this map shows it http://www.imperial-library.info/sites/default/files/gallery_files/minibigmaproadslore31gv.jpg lol so my bad typing can't screw it up lol

This is correct.

In the beginning, there were the Ehlnofey and the Hist.
Hist are immobile and unchanging, Ehlnofey are fluid and prone to subgradiation.
Some Ehlnofey wandered away from the Tamri-El.
Later, some of their children returned, such as the Nedes and the Yokudans.
The Akavir have also tried more than once, but were repelled each time.