Is it possible to add my personal custom list of words to the company database. Kindly guide me in a simple way. I am not a programmer.
Can't give you an answer regarding Company, but I would assume that it provides that possibility.
Otherwise, the built-in, old but still very useful library
completion.el offers that possibility. From the doc (which is only in the file's
;; SAVING/LOADING COMPLETIONS ;; Completions are automatically saved from one session to another ;; (unless save-completions-flag or enable-completion is nil). ;; Activating this minor-mode (calling completion-initialize) loads ;; a completions database for a saved completions file ;; (default: ~/.completions). When you exit, Emacs saves a copy of the ;; completions that you often use. When you next start, Emacs loads in ;; the saved completion file.