i am new and need something more secure than bitcoin core to store my funds, what is a better option for me trezor or ledger nano ?!...
also how to use the wallet to send funds to a BTC address, do i have to manually write it on the screen or what

I personally think that the Ledger Nano S is more user friendly, as it supports more coins etc, but i think it really comes down to personal preference, and how much you want to pay. Ledger is ~120$ vs Trezor being ~100$, so there's really not that much difference there..
Read some reviews about the two maybe?
https://blockonomi.com/trezor-vs-ledger/also how to use the wallet to send funds to a BTC address, do i have to manually write it on the screen or what

What exactly do you mean? From the wallet you currently have to your trezor/Ledger? You could just copy & paste the receiving adress for said coin on your hardware wallet ( ledger/trezor), and use that as the "send-to adress" in your current wallet.
(Always check if you copied the right adress, there have been instances where people lost their coins due to clipboard malware!)