if you want to access the Pi using SSH,in the first place you need to get your SSH server enables using Raspi-config.
sudo raspi-config

after that you need to get your RaspberryPI IP . you can easily get that by typing

ip addr | grep ‘inet .* eth0’

lets say that you got this result from the command above :

inet 192.168.2.109/24 brd 192.168.2.255 scope global eth0

now you can start SSH from the command line, passing it the Pi user’s IP address. you will be asked to enter user’s password

ssh pi@192.168.2.109