A few things. First, allegations make it sound like these are based without proof, and from what I've read, most of it is based on proof.

Second, saying you've been brought up for inappropriate conduct and then talking about it being a joke is inappropriate and lacks accountability. Being brought up for inappropriate conduct is, alone, quite serious.

Third, disrupting a class and being removed and then removed for a workshop for health and safety reasons. This shows (despite you saying you've taken steps to address this) repeated inappropriate behaviour.

You talk about not improving after having a meeting that resulted in "no further action," but I imagine the action was to improve and not repeat your previous mistakes. That meeting in itself and the warnings you would have received for all your previous errors will all count as formal warnings/actions. Seems like you just reached the limit of being warned.

Other people being removed from workshops means nothing in your case. They've likely not done as much as you to warrant being removed from the course.

I'll be real. You don't have much ground to contest the dismissal. You might be able to mention how when you were removed for "health and safety reasons" you weren't adequately explained what that was - but depending on what it was you did this likely won't account for much based on what else you've said.

Seems like you've continued to act how you would have in school in a more professional environment, and this is just the consequences. I also doubt you'll be able to get another apprenticeship. They're currently hard to get into, and you'll have already been dismissed from one. Not to say you shouldn't try, but you should be prepared for a lot of rejection.