Before setting up your league for a year-end outing, there are some things to consider.
What Do You Want to Get Out of the System?
Are you just wanting to print scorecard cards? That's generally the only reason you would want to set this up. An outing generally doesn't affect the league, and if you set the rounds up as normal rounds and enter scores, it would affect stats, handicaps, and overall league standings. An outing should usually be set up as a "fun-night" in the system, which allows you to set a schedule so you can print scorecards, but doesn't allow you to enter scores.
2-Player Team League Scheduling Considerations
If you're a 2-player team league and want to schedule 4 random players together, you cannot. You can only schedule one team with another team. This means that in order to be able to do this, you'd have to change the teams around, set the schedule, print scorecards, then change the teams back where they were.
Tracking Skins
If you're only looking to figure out skins for the day, I have free spreadsheets available that you can use for a one-off round of golf that doesn't require all the setup changes
If you're a 9-hole league, in order to set up an 18-hole outing, you have to set two 9-hole rounds for a single day. Each round is treated as completely separate, so if you're playing skins and entering scores, each 9 holes is computed on it's own with separate pot. Check out this help video which walks you through the configuration