Speech delay mild autism

Hithere,
My son is 4.8 years old he has mild autism high functioned non verbal only start vocalising and says bye bye.main issues are:
Speech delay
Often constipated ( stool is so mushy sticky and smelly)
Less focus,short span of attention
Stimming alot running, jumping here n there scream and shouts when get excited, hand flapping and press hands while playing.
Picky eater has sweet cravings wants to eat chips and chocolates.
Weak muscle very weal grip of pencil but hold things nicely otherwise.
Does not look interested in self eating
Not potty trained

He met all his milestone timely like he start sitting by 6 mnth of age start walking after his first birthday. Never developed a speech.
He born via c section all pregnency was fine, his birth weight was 2.6 kg. Doctor induced myself for speedy delivery and then he passed stool inside so doctor had advised for c section.
He is non sharing
Get stubborn and does not like much interaction with his baby sister.self explorer always into search of toys or chocolates if he goes out.
Right now he is on glutenfree casine free diet which help him in his constipation not completely but better. Also he had tooth decay and have 4 fillings.

Pleas note i am totallt new to this homeopathy world and i dont know any terminology so please guide me what to start to help my son.thank you