So start each day really early (like 5:30 or 6am) and have a plan so you can park where you want to park. I’d pick up the “day hikes of glacier national park” map at the visitor center, which has a ranking of all the hikes in addition to being a great map.
When we went you could only get as far as avalanche by car and Logan Pass by bike. Avalanche Lake is a beautiful hike as is hidden lake up at Logan pass.