There is little known about life before the Fall, but what we have is instructive.
First, we have God's work in Creation:
"And on the seventh day God ended His work which He had made; and He rested on the seventh day from all His work which He had made." (Gen 2:2)The Hebrew word here is מְלַאכְתֹּ֖ו (mel-aw-kah). It can be used for ministry, or deputyship in addition to "work". It is not used for servile work. It is used again in verse 3 (repeated reference to rest from His work). After that, it does not appear until Exodus.
The work for the man (Adam) is described differently:
"And the Lord God took the man, and put him into the garden of Eden to dress it and to keep it." (Gen 2:15)The word dress here (עָבְדָ֖)(aw-bad) is usually translated "serve" (also in the context of work). In fact, in 290 uses, it is translated "serve" 227. It is translated "dress" only twice (Deut 28:39 being the other one). Usually "dress" comes from a different word, meaning "do".
("Keep" here means "guard", which is the subject for another day)
Finally, at the Fall:
"In the sweat of thy face shalt thou eat bread, till thou return unto the ground" (Gen 3:19)So we see a difference in the work of God, and the work of man (not surprising). The man's work, even before the Fall, is servile (in service to God) - possibly even hard.
At the Fall, we see man's work changed. Now it is literally "sweat" (zay-aw) to get bread. This might refer to conditions changing to cause sweat when working (perhaps due to a change in diet - garden vs. bread), but seems to more refer to "frustration". Before, the work was rewarding and pleasant - now it is tedious and often spoiled.
Man's work was created on day 6 - before God rested, saying everything is good. The Fall has brought frustration and sweat.