I've always told my pupils to think of their lesson as part of a drink of cordial...

The lesson is the concentrate, but the drink isn't complete until you add water in the proper ratio... which is the DAILY practice.

There is no harm in learning the basics on a nylon-strung guitar - in fact, you'll be playing reasonably well a lot sooner because the strings are easier on your fingers. Moving from a nylon-strung to a steel-strung isn't so difficult - and you may (as I do) decide you like to play both for different things.

You'll soon know when the instrument is holding you back - just accept that you learn to crawl before you learn to run.

I'm afraid that electronic tuners have made people develop 'lazy ears' - I can (and often do) tune someone's guitar at the folk club far quicker by ear than they were doing with a tuner. I do accept that tuners have their uses, especially in a group... they're not for me, though!