We bought a dog in January 2016 from a rescue centre I have had dogs before but never had a rescue dog didnt know what he was just fell in love with his big brown eyes . Dont have much background on him as he was found in the streets he was chipped but obviously his owner didnt want him back but what i do know is

Jaxon is 2 - 3 yrs old and is a cross Akita / Rottweiler (weird combination i know never heard of such a comb)

Anyhoo he sits on command , lies down even high 5's you and is so loving and laid back his problem is when he is out . I think he may of just been locked in a garden because if i let him off his lead on the field he just runs up and down where the fence is no stop and he doesnt just run he sprints everywhere he wont come back on command in fact he just ignores u have tried to get him back with toys give him a treat when he does come back when u shout of him which is very rare we now have to keep him on the leash at all times which is unfair as he also gets too excited when he sees others dogs and growls when he plays and the other owners think he is being aggressive so now no-one will come next to him my partner bought a collar which i didnt agree with what vibrates to get the dogs attention when he is ignoring u but that was a waste of money we have tried whistles and am running out of ideas if anyone has got any will be very much appreciated xx

Start training recall in the house where there is less distractions. When doing it out on a walk have him on a long line so that way he won't have the option to ignore you as if he does gently reel him in.
Do you do anything to work his brain?

Not awfully relevant to your question but as he was a stray, no-one can say he is a Rott x Akita. That is pure speculation, I'm afraid.

He maybe that cross then again he might not. Its well documented that akitas have high prey drive and can be at times dog intolerant so at this time I would keep him on lead and book him onto group kcgc classes so he can learn to be social around dogs and humans alike.
Both breeds are very dominant and need firm but fair training, do not do anything Cesar Milan type, rotts I know don't respond well to that type of training. As you don't know his past its quite possible he wasn't well socialised with other dogs so doesn't know how to react correctly to them. A lot of dogs can get reactive on a lead but without reliable recall its not good to let him off at this time. I wouldn't push this but start with the very basics and don't push him too quickly, he needs to learn to respect you and this can take time with a new dog.