Hamsters are fairly easily entertained. Make sure to provide an interesting setup, full of toys and foraging mixes. Adding cork tunnels, and bark will offer cracks to hide and search. Grass huts and tunnels make comfy nests and great toys to decimate
Toilet tubes with treats stuffed in the middle, and toilet tissue stuffed into the sides makes an excellent brain toy. Offering at least 12 inches of bedding (for a Syrian) or 6-8 (for a dwarf) will provide plenty of opportunity to create burrows. You can also offer treats like Whimzees, Greenies (in moderation as they contain gelatin), or other hamster safe dog biscuits. Scatter feeding is also something that will keep your hamster very occupied
Occasionally add in a new toy, and your ham will love the new item they now have to investigate. The key is just ensuring you have opportunities to climb, run, and burrow. Then you'll have a happy hamster