1. Upgrade to version 21.04 if you haven't already done so.
2. Start a new game in 2018.
3. Go to Advanced Tools on the Tools Menu.
4. Click 'Download Team Logos'.
This should take less than a minute.
When you're done, I recommend clicking "Download Player Photos". This will take a bit longer (5-10 minutes), but it will download and resize photos for about 4,000 players in the 2018 database.
All art is permanently saved to the "downloads" folder. You don't need to repeat these steps every time you start a new game.
Play One Day will sim all the games for that day. But you don't need to sim each individual game to have control over the lineups. Turn on Commissioner Mode (in the upper left corner of the "Options" dialog in the Tools Menu). This gives you control of every team, and the computer manager won't alter the lineups you set for each team (unless someone is unable to play due to injury).
If you want to set the lineup for each team at the very beginning of the game, with access to head-to-head stats against the opposing pitcher, follow these steps: