... Scafell pike... What it is like in comparison to Nevis and Snowdon?
(My notes below assume reasonably good weather and summer conditions.)I've only walked up Ben Nevis once but walked up Scafell Pike and Snowdon frequently, each by several routes.
Personally I found Ben Nevis (from Glen Nevis via the 'tourist path') by far the most tiring - approx 4,300 feet ascent in ten miles walking.
For me, Scafell Pike (from Wasdale NT carpark at Brackenclose) is less tiring than Ben Nevis - approx 3,000 feet in six miles walking.
Snowdon (from Pen Y Pass) I find much the easiest - approx 2,300 feet ascent in about seven miles.
IMHO, Ben Nevis has the easiest path to walk on; the Pyg track is rougher; and the higher sections of the Scafell Pike path are rougher still.
In my opinion, Scafell Pike is the least straightforward for navigation, especially on the descent. On Snowdon, the Pyg track is fairly straightforward to follow. The path up Ben Nevis is the least challenging for navigation (but beware the gullies on the final ascent).
If you've walked up Ben Nevis and Snowdon without any problem, you should have no particular difficulty on Scafell Pike. But that's just my opinion - mountain walking is a subjective experience.
Enjoy your walk - I hope you get a clear view and hope it's not too crowded.