The first proto-Norse culture appeared in Northern Europe around 1700 BCE, growing out of the hunter-gatherer Pitted Wares culture of southern Scandinavia, and the Indo-European-derived Battle Axe culture of the Scandinavian peninsula. This merge kicked off the Nordic Bronze Age. This new culture practiced animal husbandry, agriculture, and facilitated trade with Mycenaean Greece.
What’s known about the mythology of this time remains very fragmented, but archeological finds suggest a strong presence of sun-worship. The proto-Norse also seem to have made a mythological connection between the sun and horses, with the motif a horse pulling the sun like a chariot. This motif survives in Norse mythology in the form of Skinfaxi and Hrímfaxi, the horses who pull the sun and moon.
Beyond that, it’s impossible to say for sure if the proto-Norse venerated any gods similar to those found in the contemporary Norse pantheon.