First time player pleeease help😁😁😁

So for context I have never played halo but have seen a summary of the whole lore of halo as a kid because I did not knew at that time that I would get a chance to play this master piece

My doubts-

I have started playing halo MCC recently so wanted to ask am I playing the og halo

I have started from halo CE this is the right order right??

And why is there no backstory or context at the start of halo CE (MCC)

Please my senior veterans please help your junior