Going from Egypt to Israel would've probably taken a couple of weeks, maybe a month at most. However, the original plan anyway had the Nation of Israel taking a longer route out of Egypt to lead up to the splitting of the Red Sea. After that, there was a little over a month leading up to the giving of the Torah at Mt. Sinai and then forty days of waiting for Moses to return from heaven. This is where the bigger delays started: The Nation of Israel sinned roughly forty days after the giving of the Torah with the Golden Calf, leading to forty days of repentance and then another forty days of waiting for Moses again to return from heaven. About half a year had passed from the Exodus at this point. After that, work on the Tabernacle started, which was finished roughly half a year later.
Now, if I remember correctly, after the building of the Tabernacle, the Nation of Israel got back to going to the land of Israel and sent the spies. Had the spies not turned Israel against the objective of entering the land of Israel, they probably would've reached it a week later.
Since Israel sinned with the spies, they were punished by remained in the desert for another 38 years, and they arrived in Israel at the fortieth year to the Exodus.
