The number of accounts you can follow/unfollow on Crowdfire differs across free and paid plans.
On the Free plan, you can follow/unfollow 10 accounts per Twitter account. This count is reset every 24 hours. So in order to take more actions than 10, could either upgrade to a paid plan or wait for the count to reset in 24 hours.
All paid plans
There are no Crowdfire limits for follow/unfollows on the paid plans. Third-party apps like Crowdfire are allowed to show 500 results for your followers and non-followers every day. So you can take actions on these number of accounts without any trouble.
Do note that the Twitter daily limits still apply. These limits aren't a specific number and differ across all Twitter accounts. That's because these depend on a lot of other factors like the speed of which you follow or unfollow, how often you use the native Twitter apps etc. Whenever you do hit the Twitter limits, just avoid the use of third-party apps like Crowdfire for next 24 hours and use the native Twitter app for a while. You should be able to resume your activities like normal soon!
Read more about how you can avoid hitting Twitter limits here