en_tn/gen/28/20.md

vowed a vow

"made a vow" or "solemnly promised God"

If God will ... then Yahweh will be my God

Jacob is speaking to God in the third person. This can be stated in the second person. Alternate translation: "If you will ... then you, Yahweh, will be the God that I will worship" (See: rc://en/ta/man/translate/figs-123person)

on this road on which I am walking

This stands for Jacob's journey to find a wife and to return home. Alternate translation: "on this journey" (See: rc://en/ta/man/translate/figs-metonymy)

will give me bread to eat

Here "bread" stands for food in general. (See: rc://en/ta/man/translate/figs-synecdoche)