That sounds like a neat idea for an Rp world but I don't think its possible to make a timer using HTML ^^; There are free timers widgets online that people can put on their pages out there, as with playlists, counters etc... but these things don't work on toyhou.se!
And that's fine! Heres a good site to learn HTML (Bootstrap too) : https://www.w3schools.com/html/default.asp