A general advice to anyone not wanting to experience this: When you create a new wallet which is not based on a mnemonic seed, no matter which coin, make a backup first before you transfer any coins into the new wallet. Preferably two backups to two independent devices (optionally encrypted with VeraCrypt)

When you create an HD wallet based on a mnemonic seed obviously you should immediately write down your seed on paper, preferably on two different papers stored in different locations, before sending any coins to the wallet.

That way the private keys are backed up and secured and you won't lose your coins if you do something stupid.

And no, taking a photo of the seed with your mobile phone is not good. You will eventually delete the photo, it will get lost when the SD card dies or someone will find it on your cloud storage and know how to use that seed for himself. Write it down and store it with all other papers and documents that you keep for your entire life.