Setting up web access to MBL ... questions

i think i want to go with FTP to access and pull files from the drive remotely. but i’m first trying to grasp how FTP works. there is also secure FTP (SFTP) which i’m looking into. i think i need to use filezilla client on the machine i wish to use to access the drive, but some questions i have are: if i configure port forwarding on my router to allow FTP access to the drive, which ports should i open so that the drive can be accessed ? i don’t leave my computers on all the time, but the NAS is always on as well as the router, so if i set up FTP access would that allow me to access the NAS directly ? my router uses DHCP but i have made IP address reservations for each device on my network. my devices are set to DHCP, but the router always assigns the same IP address to each device. i use verizon fios internet, so i’m not sure if my ISP IP address is DHCP or static, i never really plugged into the modem to configure it. so i am not sure how to go about figuring out the address or hostname i need to have set up in order to find my network from the internet …