To get an overview of the Glacier, consider hiking the Toe of the Athabasca Glacier Trail. As the name implies, the uphill path travels towards the 'toe' of the glacier.
With the glacier receding so much, it now ends significantly before reaching the ice. It is still worth it, however, and the interpretive signage provides some educational insight.
Although this trail is quite short, keep in mind that it follows the route of the receding glacier and the surface is therefore rockier than a regular hiking trail.
If you want to walk on the ice, join a guided Columbia Icefield Adventure tour ($$$).
A Parks Canada parks pass is required to drive the Icefields Parkway ($22/day for a vehicle of up to 7 people).