The best powders to start with are "ball" powders, called that because of their shape. They measure very well. Easy to throw accurate charges.

Tac, BLC2, AA-2230, and H-335, ball powders, listed in my order of preference.

Extruded powders like Varget are great for precession loads, but can be difficult for a beginner to throw from a powder measure.

Other extruded powders suitable for 223 are, IMR-4895, IMR-3031, Re-15, and IMR-8208 XBR my favorite of this group.

The burn rate of your gunpowder choice should be matched to the bullet weight you want to shoot.  The way to discover what this means is by sitting down with load tables and paying attention to which gunpowders are used with each range of bullet weights.  As you move from light to heavy, you'll notice a shift in the gunpowders listed with each bullet, with considerable overlap across weights.

There is no best gunpowder, everything we have to choose from is great, but there are better choices for one reason or another.  Metering through a measure is a pretty good reason, and the ball powders meter best, but the fine extruded powders meter almost as well, so sometimes there is no clear preference.

Sometimes we have to choose a gunpowder because it's available locally.  Which brings me to another point.  When you start, buy one pound containers until you decide which gunpowder you want to settle on.

I'm a fan of Reloder 15 for bullets ranging from 52 grains weight to 80 grains.  This one is a little slow for the 52 grain bullets, but it fills the case and just works great anyway, and still produces over 3200 fps in my 24 inch barreled gun.  That's pretty fast.

H335, BL-C(2), W748, andTAC are all ball powders that will work for you.  Reloder 15, H4895, IMR 4895, and Varget are extruded powders that work.  There are probably another 8 that I could name.

What that all means is that you won't screw up by simply picking one.  You might find out later you like something else better, but it will be for relatively minor reasons.

Here's the load for 52 grain MK's I have posted here ad nauseum.

Winchester cases
Remington 7 1/2 primers
Sierra 52 grain MatchKings
&
27.0 to 27.2 grains of Reloder 15.
Loaded to 2.25 inches COAL.

27.0 grains of RE-15 fills the case to the bottom of the neck.  27.4 grains fills the case to the mouth; this was my original load, but the case is so full that it's almost impossible to avoid spilling powder from the load block to the shell holder, so I backed down to leave a little room.  Mostly I load 27.0 grains.  The 27.4 grain charge requires very good neck tension to prevent pushing the bullet out of the case.

This gunpowder is very slow for this bullet and I found that 26.8 grains is so little that the chamber is not sealed well.

I started using this load when I had the naive notion of loading my rifles with one gunpowder.  I wanted a load for shooting 100 yard reduced course Highpower matches, I had bullets bought from the seconds barrel at Sierra, gunpowder I was using for my full distance loads, and so this load followed naturally.