OK lots of ways to do this, here's a few:
Open a sequence, and then double click the imported video to open in the source window, go the beginning of what you want and press "I" to mark the in point. If you are cropping anything off the end of it, you can also find that point and press "O" for outpoint. Press the full stop "." button and this will insert the clip from in to out into your sequence wherever your playhead is. (if you have in/out points marked on your sequence it will use those instead)
in the screenshot you've shared, use the Select tool (shortcut V) to click the empty space in front of the clip. It will turn grey as selected. press delete and that part will delete so any clips on the end of it will be pulled to the beginning.
Or drag the whole clip to your timeline, and put the playhead at the beginning of where you want to cut to. Press B for the ripple edit tool, and then click and drag the beginning of the clip to the playhead and it will remove the front portion of the clip and pull the remained of the clip back to the beginning of your sequence at the same time.
I've used PPro for some years and I don't want to be patronising but this is quite basic stuff. Any basic set of tutorials shouldcover this, I recommend you find some free youtube tutorials and learn the basics - it will really help you understand how PPro works and save you asking lots of questions and waiting for answers. If you've gone through a proper course for this, please accept my apologies and send them a note requesting a refund and ask them why on earth they didn't cover the core tools!
Edit: also on the first point - you don't have to have a sequence open. Follow it up to pressing the full stop button, and instead of that click on the filmstrip icon below the video:
and just drag this into the empty space where the sequence is when it's open. PPro will auto create a sequence for you and just put the in to out part of the video at the beginning.