software to help with speedrunning and goldenberries

[i miss everyshot]

I'm new to the game and just finished chapter 9 and the moonberry, i decided that i want to do all golden berries and maybe even speedrun but i need the software which you can practice on a specific room that you choose does anybody knows how is that called?

[Clantis]

the debug mode allows you to open a map and teleport to any room. it can be enabled by manually editing the settings.celeste file, or by enabling it in the mod options if you have everest (this games modloader) installed.
tab opens the map by default in vanilla, f6 by default on everest

the speedrun tool mod has various features, but the relevant feature is savestating, allowing you to save your and every entity in the rooms position to restore instantly.
https://gamebanana.com/tools/6597

everest modloader is installed via the olympus mod manager: https://gamebanana.com/tools/6449

note that the speedrun boards dont allow you to submit runs that were played on everest, so do your runs on vanilla (opened via olympus, or by holding right on the title screen)