@AppleRepairLady If your son is planning on participating in any of the 4 official tournaments (Rocket League, Rainbow 6 Siege, Overwatch, and League of Legends), then I would suggest making sure the PC he games on will meet and exceed the minimum system requirements for these games, and preferably at the recommended specs . Otherwise, just make sure whichever game he has in his collection he will be playing at the event will be supported by the PC he can bring.
Rocket League System Requirements: https://support.rocketleague.com/hc/en-us/articles/360020051214-What-are-the-minimum-system-requirements-on-Steam-
Rainbow 6 Siege System Requirements: https://support.ubi.com/en-us/faqs/000024693/Minimum-Requirements-PC-RSIX7/
Overwatch System Requirements: https://us.battle.net/support/en/article/65159
League of Legends System Requirements: https://support.riotgames.com/hc/en-us/articles/201752654-Minimum-and-Recommended-System-Requirements
Other games/events mentioned by Dreamhack as popular at the events include build-offs in Minecraft and Terraria, private free-for-all servers in PUBG and Fortnite, and 32v32 brawls in Quake and UT.
Alternatively, you can also check system requirements for other games at https://www.systemrequirementslab.com/cyri
Your gaming laptop will have no problem playing any of the 4 listed official tournament games.