Depends if Bulma or Gohan had told Trunks about Garlic Jr. If so, he doesn't intervene and the timeline goes on as usual. If not and Trunks shows up after the Black Water Mist has been neutralised, Trunks causes the arc to end a lot earlier before flying off until Mecha Freeza shows up with the only change being the Z-Warriors hold onto their questions for an extra couple of months.
If Trunks arrives and is affected by the Black Water Mist, he kills Gohan and Kuririn and subdues Piccolo until Garlic Jr. can use the Dragon Balls again, likely using it to replicate the Black Water Mist to the extent he can try and spread it across the galaxy. Piccolo is then killed. Goku arrives months later once he perfects Shunkan Ido and fights Trunks and Garlic Jr. Goku overpowers Trunks and destroys the Makyo Star to defeat Garlic Jr. Trunks then tells Goku everything once the Black Water Mist is stopped, but travels back home once realising this future can't be saved now. He returns to his timeline and refuels the Time Machine, going to a timeline similar to the main one with the only difference being Trunks is almost 20 when he kills Freeza.
Meanwhile in the ruined timeline, Goku decides to do the same strategy as in the Cell Games wait and makes a Namekian from the Dragon clan Earth's new God with a new set of DBs, though it may not be Dende due to him perhaps having not finished his training yet. After that, things go exactly as in canon minus Piccolo knowing about Trunks. To make up for that, Trunks' additional time in this era and privacy not being so essential would allow him to write things down for Goku in hopes he may still change something.
As for the ToP, Goku and Vegeta not developing CSSB due to the Future Trunks Arc not happening in the first timeline means they lose to Jiren before Ultra Instinct can happen. Universe 7 is then erased and not revived.