How can I know my time spent in hours to finish my front end development ptoject?

How can I know my time spent in hours to finish my front end development ptoject?

Not sure if I understand your question. You can see for all projects/tutorials/algorithms when you completed them here. In order to know the hours, you should have timed it yourself in some way.

For tracking your time you can use Pomello (if you use Trello) or Wakatime (plugin for your editor).