The urheimat Pontic-Caspian steppe hypothesis suggests Ukraina as the probable location. Anatolia or Armenia, also on the Black Sea, are possibilities. The Ukraine is probably also where the horse was first domesticated. The Kurgan hypothesis, formulated by Gimbutas, suggests nomads on horseback in the 3rd millennium BC. It has been inhabited since 32,000 BC. The main alternatives are the other side of the Black Sea: the Anatolian hypothesis and the recent Armenian hypothesis, based on aDNA research. Kievan Rus was the first big city in the Slavic world, centred on a Viking route down the Dnieper. The Crimea spoke a Norse dialect.
There may be 4,000 words in English traceable to PIE; some of which have cognates in Ukrainian. The least changed words in the whole PIE family are the numbers one to six, and ten:
odyn dva try chotyry p’yatʹ shistʹ sim visim dev’yatʹ desyatʹ Ukrainian
ēka du’i tina cāra pām̐ca chaẏa sāta āṭa naẏa daśa Bengali
un dau tri pedwar pump chwech saith wyth naw deg Welsh
The PIE tree looks like this: