during my research I was recommended to use electrum wallet but I was confused if electrum wallet is an exchange or a custodial wallet, therefore i need a good direction, clarification and update of suitable wallet from senior colleagues.
This is such a great question you have asked. And since you mentioned Electrum wallet, another user has recommended it. I second that. Permit me to go further and provide you with some user experience.
I have been using electrum wallet for my Bitcoin storage for the past couple of years and no time have I encountered any issues. I love the regular software updates it gets, meaning that you are sure of having the latest security patch and bugs or malware trying to steal your funds. During the time Bitcoin experienced next congestion where the transaction fee was pretty high and I was able to use the fee customization feature which helped to a degree. I don't have the mobile version of the wallet but I totally recommend the desktop version. I also love the multiple address options too. There are also hardware wallets too. Since I do not have experience using any of them, I'll let other users share review.