Hi, is this 2/3 times just for play and are you taking him out to toilet other times?
Personally I would only be taking him out for 10 minutes at 10 weeks old at a time to run around (as I would be using the same rule as walking them which is 5 min per month of age until they are nearly a year old)
In this 10 min in the garden I would do some training with him, let him sniff around then to start when he looks up towards you I would run away and when he chases you I would call him and stop and when he gets to you to praise him / make a fuss of him - this will help with his recall later.
I would also be taking him out in the car and carry him around town to get him socialised with things like cars, lorries, (in normal times, which we are not in, unfortunately - I would also take him to the supermarket (still in your arms ) as then he would meet loads of different people who go ooo ahhh)
If you can take him (still carrying him, until he’s had all his vaccinations) and let him see horses, cows, sheep etc.
Once he is fully vaccinated I would do all the above but this time with him on a lead and on the ground - but only for short spells.
Hope that helps