How Old Is My Account. and how do i check?

the only way i know how is to go to the email you registered with and look for the welcome email they send you. maybe you can write a ticket in and they might be able to help you there

If you played ranked, you can see what season first u played in at op.gg

I'd like to know this as well. I thought Wasted on LoL told you this stuff but it looks like it's been updated/streamlined to focus solely on the amount of time rather than number of games, date of first game, and such.

I think I remember reading somewhere that Riot doesn't tell players when they made their accounts anymore for some reason, can't remember what it was. Some ways to figure it out that I know of is either remembering the first champion released during your time playing (for example, mine was Vel'Koz, so I started early season 4) or you could look in the skin tab and sort by date, whenever the skin tab is working again, to get an idea based off your first skin.

if you remember your first champ played, you can search your match history and filter for just that champ to make the list a lot shorter..than scroll to the bottom