Well done for giving Ollie his freedom - you just need to train him well now to come back when you call/whistle and then hopefully when he hits his teens he won't be too much of a problem. Young pups do tend to stay fairly close but when they get to adolescence and get a bit more confident..........
My trainer always said " do not mistake the puppy's need to follow for good recall" - how right she was. At 7 months Coco seemed to forget all her training and decided to do just what she wanted. I still gave her as much freedom as possible but it was hard work at times
The early training is crucial though so that when they gets over the teen phase they remember their training.
As for picking up trash when out walking, it is a tricky one. You got off lightly with a lipbalm
- Coco usually finds revolting stuff usually like a full poo bag, condom or a deer's leg to give a few examples
It is great treasure to them so you need to teach Ollie to swap his find for something with you. Never chase after him as he will think it is a game but teach him a reliable "give" or "leave" and swap the offending item with a treat or a toy. It may not always work but most of the time - you really need a high value reward with you at all times to make it worth swapping. Coco was not about to give up the bag of poo though - would need to carry a whole roast chicken in my pocket all the time to get total reliability from her!
Keep up the good work - sounds like you are doing a great job and I am sure Ollie is loving his freedom.