See vim.fandom
In normal mode:
ma -- set mark a
'a -- jump to line of mark a (first non-blank character in line)
`a -- jump to position (line and column) of mark a
d'a -- delete from current line to line of mark a
d`a -- delete from current cursor position to position of mark a
c'a -- change text from current line to line of mark a
y`a -- yank text to unnamed buffer from cursor to position of mark a
:marks list all the current marks
:marks aB list marks a, B