Viewing accepted solutions, be it after solving a kata or after unlocking them, is one of the best ways to learn. Other users could have different ideas for solving the task. Their solutions can be clearer, shorter, faster, or use functions you did not know existed. You can learn a lot while studying them, and it's very often worthwhile to at least briefly read over them.
If some solution caught your special attention, you can write a post in the solution's discourse section to praise it, criticize it in some way, or ask questions about it.
You can vote on other user's solutions to help uncover the best ones. There are two choices for voting:
Best practices are for solutions that you think are a good combination of being maintainable and efficient. They may not be the fastest solution - if the fastest solution involves overly optimizing the code in a way that becomes hard to read.
Clever votes are for solutions that you feel like are notable in some way, but not something you would expect to see in production code.