There are 6 optional collectibles in Episode 1: Roads. Each optional collectible will unlock a specific achievement / trophy. If you have completed the episode, you can go back to specific chapters in collectible mode and not affect your decisions in the episode.
Here are the timestamps for the collectibles:
0:33 - #1 Forest
2:16 - #4 Outside Gas Station / Minimart
3:15 - #3 Inside Gas Station / Minimart
3:15 - #2 Inside Gas Station / Minimart
4:18 - #5 Beach
5:25 - #6 Inside Motel
Here is a video guide with English commentary!
Here is a playlist of guides for this game!
https://www.youtube.com/playlist?list=PL-HeW6XkKdUJNaduS4UQz...