For a beginner brush I like one of:
OMEGA 10098 PROFESSIONAL BOAR SHAVING BRUSH -- less than $15
or
a Silver Tip Badger 22mm knot at about $100
HEINRICH L. THATER SERIES 4292/3 H 22MM FINEST BADGER SILVER TIP
or equivalent.

Brushes are worth shopping for. That is why the Omega Boar brush is at the top.
It is a darn fine durable boar bristle brush and while it takes longer and more work to make a great lather
it will do the job. I have two marvelous Thater badger brushes and am very pleased. The other
badger brushes I have are Dovo & Art of Shaving all nice. I was just looking and some good
brushes are less expensive than when I bought my last.

There are a couple grades of badger so get a good grade in a nice brush handle and stand (or make a stand).
Most badger knots are made in China and so all good brushes begin with much the same choice of knots.
Pay attention to the size of the knot and loft of the brush. Big dense lofty knots are expensive, when you
retire and have an extra buck or two hunt a world class 28mm knot like I did ;-) they are fun.
Find a handle that looks like a shave brush to you that also fits your hand.

Horse hair and artificial bristles satisfy religious needs for some, Boar is "pig" and
artificial works for vegans. Gathering horse hair does not kill the horse so some like it
for that reason.