Newbie help needed!

Hi....I have been using PS Elements & Photos on a Mac for many years, and want to change over to LRC.   I have done lots of reading etc but am getting more confused.    Currently I import and store my days photos into Photos, and save on an external hard drive keeping the original file names, and then delete the unwanted ones from Photos......... then upload to my website.

What I woud like to do is to import the photos, go through and delete the unwanted ones, change the file name to sequence (now there will be gaps in original file names from the deleted ones)......then export the new file name/sequence photos to my website.

Where do I start?  How do I get the newly named sequential photos onto my hard drive to save as the originals?    Some of these would be edited at a later date in LRC and saved/sent to clients.   I would create a new collection each day for the photos, and delete etc from there.....