Stop following that tutorial and follow one that actually teaches you stuff instead of just telling you "Do what I do".
I recommend this one by Cadiboo
The filenames of some of your mods suggests you are not getting them from official sources, please read my signature for more info on why this is a bad thing.
At least one of your mods is broken/poorly made and will not work on a server.
Why were you trying to compile manually with javac?
Your current version of Gradle(or the gradle wrapper) is incompatible with Java 11, try Java 8 as that is what Minecraft targets.
This is the bit that concerns me:
[19:52:40] [main/WARN] [mixin]: Reference map 'movingworld.mixin.refmap.json' for mixins.movingworld.json could not be read. If this is a development environment you can ignore this message
[19:52:40] [main/INFO] [mixin]: A re-entrant transformer '$wrapper.sereneseasons.asm.transformer.WorldTransformer' was detected and will no longer process meta class data
[19:52:40] [main/INFO] [mixin]: A re-entrant transformer '$wrapper.com.pg85.otg.forge.asm.OTGClassTransformer' was detected and will no longer process meta class data
[19:52:41] [main/INFO] [STDERR]: [com.pg85.otg.forge.asm.OTGClassTransformer:transform:141]: java.lang.RuntimeException: OTG is not compatible with this version of Forge.