Welcome Rainbow.
My son's 10 diagnosed with autism (though now, admittedly more of an Aspie) aged 4 yrs. His speech is good, he's a good communicator and WANTS (though suffers terribly with it) to make friends.
When he was sort of 6/7/8 yrs old, as a single parent and with him an only child, I tried all the usualy social outlets for him. Gymnastics, swimming lessons, Beavers, football at the local leisure centre. He always had extra help and I never left him, was always a "mummy helper" BUT, it was all too much. He just found it so very stressful.
Now, years later, he is quite the recluse. He finds it hard to go out of the house (at all) and though we encourage it, he finds it difficult when another friend visits us for tea after school (that sort of thing). We have to keep these events short and sweet and be guided by him. I usually end up playing Jenga or somesuch with the visiting child whilst my son sits in his room worrying if he's been "mean" to the other kid cause my son's had enough.
It's a touch one this. Yes, try the social thing with him (if he's up to it) but, not so that it causes him stress.
My son's just been diagnosed with full blown OCD (a nice little bedfellow of autistic spectrum disorder) and I wonder whether it's his way of saying "ffs....leave me alone - I can't be like "that"!"
No one tells you which way is best. Every situation is different. I've read many books and find Tony Atwood the one where I had many Eureka! moments because IT WAS MY SON ON THOSE PAGES. I also have a book called "It's So Much Work to be Your Friend- Helping the Child with Learning Disabilites Find Social Success" by Richard Lavoie. It's an American book. It's excellent - I got it from Amazon.
Good luck to you Rainbow and you'll find lots of support on here.