Makiyayi yana kiwo shanu da awaki a wajen ƙauye.

Here Makiyayi is singular: it refers to one herder.
If you wanted to talk about several herders, you would normally say:

• Makiyaya suna kiwo shanu da awaki a wajen ƙauye.
  The herders are herding cows and goats outside the village.

In yana kiwo:

• yana = he is / he does (progressive or habitual marker)
• kiwo is a verbal noun meaning herding, animal rearing, grazing animals.

Literally, the structure is like “he is (in) herding”, which is why it matches English “he is herding” or “he herds”.

Yes, Makiyayi yana kiwon shanu da awaki is also correct and natural.

• yana kiwo shanu – uses kiwo directly with its object shanu (herd cows).
• yana kiwon shanu – treats kiwon shanu as a tighter noun phrase, literally “the herding of cows”.

In everyday speech, people use both, and the meaning difference is very small or absent in this kind of sentence.

Hausa has some irregular plurals, and shanu is one of them.

• saniya = a cow
• shanu = cows / cattle

You simply have to memorize this pair saniya → shanu; it doesn’t follow a simple “add -i” pattern.

Awaki is the plural form meaning goats.
The usual singular is:

• akuya = a goat
• awaki = goats

So the sentence literally has “cows and goats” = shanu da awaki.

In shanu da awaki, da means “and”.
So shanu da awaki = cows and goats.

Hausa da can also mean “with” in other contexts, but here it is simply the coordinating conjunction and.

Breakdown:

• a – a very common preposition; here it means “in / at / on / in the area of”.
• waje – place, outside, space; with the -n ending it becomes wajen = the place / the area of.
• ƙauye – village.

So a wajen ƙauye is literally “in the area/place of the village”, which in natural English here is “outside the village” / “around the village area”.

The -n you see in wajen is the genitive/“linking” -n, and it attaches to waje, not to ƙauye:

• waje + n + ƙauye → wajen ƙauye
  place-of village

So you do not say ƙauyen here, because ƙauye is already the second noun in that genitive link (the village), and the linking -n belongs on the first noun (waje → wajen).
That full phrase then comes under a: a wajen ƙauye.

• a ƙauye = in the village, inside it.
• a wajen ƙauye = in the area outside / around the village, not inside the built-up part.

For a herder with animals, a wajen ƙauye is more natural, because grazing usually happens outside the village proper.

You mainly change the subject pronoun part of yana:

• female herder (1 person):
  Makiyayi tana kiwo shanu da awaki a wajen ƙauye.
  The (female) herder is herding cows and goats outside the village.

• several herders:
  Makiyaya suna kiwo shanu da awaki a wajen ƙauye.
  The herders are herding cows and goats outside the village.

Forms to remember: yana (he), tana (she), suna (they).

ƙ is not the same as k in Hausa:

• k is a plain “k” sound, like English “k” in “kite”.
• ƙ is an implosive / “swallowed” k; you slightly pull the sound inward in your throat as you say it.

English doesn’t have this sound, but it’s fine if, at first, you just make a clear difference (for yourself) between words with k and ƙ, even if your ƙ still sounds close to an ordinary k.