Here are examples:
The pillar of cloud, and pillar of fire (Exodus ch.13)Water given from the rock (Exodus ch.17)
The manna and the quail (Exodus ch.16)
The Ten Commandments (Exodus ch.19), and later, the rest of the Torah (Exodus 24:12)
God's presence in the Tabernacle (Exodus ch.40, Leviticus ch.8)
See also:
During the Exodus, God provided a pillar of cloud by day, and a pillar of fire by night.
In Exodus god provided manna for the Hebrew people.
God's splitting of the Reed Sea (Exodus ch.14).
God told him to (Exodus ch.3).
God's splitting of the Reed Sea (Exodus ch.14).
God took them out of Egypt with wonders and miracles (Exodus ch.12-13).
The Torah states they were fed a substance callled Manna (מן), pronounced "mahn" in Hebrew. Exodus ch.16.
Children of Israel.
I suppose you mean 'to his people in the wilderness'? God showed his presence always, by a pillar of cloud to guide them by day and a pillar of fire to guide them by night. (Exodus 13.21,22)
God split the Sea of Reeds (Exodus 14) for the Israelites to cross.
The people and Moses, depending on when. First, God spoke the Ten Commandments to the entire Israelite nation (Exodus ch.19-20), then He taught the Torah to Moses during the forty days (Exodus 24:12).
God's Torah was delivered to the Israelites by Moses (Exodus 24:12) in the wilderness of Sinai. The Ten Commandments were given to the people directly by God (Exodus ch.19-20).