Complex sentence: He left Belgrade as an infant of 3--4 months joining his father first in Kolašin, then in Morača Monastery, and finally in Titograd where Perović spent his formative years.
Split into simpler sentences: He left Belgrade as an infant of 3--4 months joining his father first in Kolašin. Then in Morača Monastery, and finally in Titograd where Perović spent his formative years.