Belgian tourist with some questions

Hi to all reading this.

Me and my mates will go on a 2 week trip to Scotland at the end of August, and we had a few questions.

• How do permits work in Scotland? Can we get a permit for the whole of Scotland, or are they local? Is there some resource online that has centralized all these permits?

• Are there some lochs/rivers/spots by-the-sea that can be recommended? Salmon, Rainbow Trout, Brown Trout and Arctic Charr will be the main ones I think.

• Any specific rules or etiquette we need to be aware of?

Thank you very much for any help or resources you might have on offer.