hey everyone, I'm new here but I want to try this, seems like fun

Newbie question, how far can I go with mixing this? Can I add effects, do automations, slicing, production stuff, adding sounds, maybe change the vibe of some parts the song (just asking what is possible, not necessarily that I want to do it! ) or am I limited to just use these tracks the way they are and use only effects/automations/eq ? Sorry if it seems a strange question but I have never done any mixing contests! And where do I have to send the final mix once finished? thanks!