1. I have an old cell phone i bought it on 2019. I installed electrum at that time and didn't update it since then (can't tell if the updates was done automatically) and then i left that cell phone since 2020. Last January i re-opened Electrum in that mobile , i found that i am not able to create a new seed (i have already three previous wallets). Anyone has an explanation?
Check where you backup your seed phrases, make sure they is correct. Delete and reinstall Electrum. Probably this should work.
2. An old laptop i use since 2019 as a cold storage. The device has windows 7 installed but never updated and an old version of electrum (can't remember the version). Should i upgrade Electrum if i want to keep using the same laptop without upgrading the OS version?
Windows 7 will still support Electrum version 4.1.5, but won't support version 4.2.0 which is the latest Electrum version.