if you read the manual, you will discover lots of things…
like having to lay down a trigger on your sequencer to hear back a sample on playback. You may also read about track solos and mutes, which you may have done by mistake (not sure- your post doesn’t make really anything clear as to what you have or have not done).
By reading the manual more than once (like I did for two weeks) you will definitely discover and be reminded of other things like making sure your recording process and triggering are ok, track volumes are up, effects such as filters aren’t preventing you from hearing anything, or any other myriad of options the OT gives you that may make it seem that you can’t “record a sample anymore.”