Where should I save my data when I sell my cell phone?

I have a question.

I'm selling my cell phone, the Huawei Mate 20 Pro, where all my data such as accounts, pictures, etc. Are on it. If I have to send my cell phone or generally just sell it, how or where should I save all my data and delete it from my cell phone at the same time? Because I don't have a second cell phone or something. I also have data in the Huawei Cloud etc.

So I like to upload everything to a cloud. Everyone has to know that themselves. Play the pictures on an external hard drive.

You should pull all pictures onto your computer with a data cable and thus save them. This should secure a large part of the megabytes / gigabytes.

Emails etc. Are usually saved where you have the hoster.

So for example on freenet.de or gmx.de

Otherwise you should take a look at WHERE your cell phone stores all the numbers. My devices use the SIM card for this, which you of course keep or on the device itself.

A friend of mine stores her entire numbers in the cloud with google emails that works amazingly well.

After you have saved your data, you can finally reset the phone to factory settings.

My brother-in-law gave me the pictures, whatsapp etc. On the cloud of my google account when i got a new cell phone. With the new cell phone, he simply saved the data from the cloud to the new cell phone again, or my xiaomi did it independently.

my old cell phone was broken. You can reset yours to factory settings after data backup and then sell it