Telegram has no end to end encryption as default. You can enable it with secure chat but that is making the chats unaviable in other devices.
I can really recommend signal, been using it as my only messaging app for years and it just is so more secure. Most people installed it too after I asked them to do it to keep contact
It does not require to share it with other people tho. Still as far as I know they save it on their servers. Signal tries to not save any metadata at all. That's great.