Scotland does have "Right to Roam" (as do a number of other countries):

https://en.wikipedia.org/wiki/Freedom_to_roam

You can, in general, walk/cycle to most places in Scotland although there are fairly sensible conditions:

https://www.scotways.com/faq/law-on-statutory-access-rights

https://www.outdooraccess-scotland.scot/

I'm in the process of walking the Munros and I'm careful to check with landowners about access during the deer stalking season - I've never had a landowner be anything other than completely helpful.

NB Walkhighlands is a superb site covering walks throughout Scotland, not just the Highlands:

https://www.walkhighlands.co.uk/

Heritage Paths is also good:

http://www.heritagepaths.co.uk