Don't delete any of them. TM should be pointed to an external drive as the destination, and if ther is no backp already there, it will start with a full backup, which can take a long time to complete. So long, in fact, that if you have continued to use the machine during the backup, it may well make more backups of what has changed since the first backup began. Each of those backups will have a name tht shows the date/time of the backup.
As for "major space," that is what a full backup takes. The other backups are incremental and don't really take as much space. However, depending on how you try to get the size of the backup, yo will get wildly differing results because of the way backup snapshots are made. And, to be honest, all of them are "inaccurate" in some way or another. Yes, it's a mess, but Apple expects TM to be pointed to a drive and then to manage the drive completely by TM. When it runs out of space, it should delete what it needs to and tidy up behind itself to keep all of the backups with integrity.