now as you have understood that transaction inputs are utxo based,
you need to keep in mind about your privacy in consolidating your bitcoin
you are losing your privacy when using multiple utxos from different addresses in a single transaction,
to avoid this you may want to consolidate it one address at a time, use a coinjoin service, or even a mixer
Thanks for reminding that and I am aware of that.
What I just am curious about is more on transaction fees, but with the help of everyone I much now understood it.
I'll look and try to research about coinjoin services since I read some cases about that here on the forum especially when the seizure of one of the biggest bitcoin mixer a few months ago.