I just shift from windows to macbook. I have files on my external hard disk whic I am able to see but not delete or move or copy new files. It has lots of important files and I cannot simple change the file system as it is full and macbook doesn't comes with lots of storage.
I have used Paragon NTFS previously, works fine. However, if you plan to use a drive with both Mac and Windows then it should be formatted as exFAT, and if it will be used only with Macs then APFS for an SSD or MacOS Extended Journaled for a spinning-disk HDD.
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
Reformatting will delete all the data you may need temporary storage. FWIW, a 1 TB SSD or a 2-4 TB HDD can be bought for <$100.
I have used Paragon NTFS previously, works fine. However, if you plan to use a drive with both Mac and Windows then it should be formatted as exFAT, and if it will be used only with Macs then APFS for an SSD or MacOS Extended Journaled for a spinning-disk HDD.
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
Reformatting will delete all the data you may need temporary storage. FWIW, a 1 TB SSD or a 2-4 TB HDD can be bought for <$100.
macOS can not natively write to NTFS volumes.
There are 3rd party products out there that will let you do this. I can't speak for any of them as I haven't had a need to do that in many years.
Do a google search for NTFS for macOS.
writing files on NTFS external hard disk
