Ask HN: Programming logic help (not language specific)

Hello HN, I am applying for BA/PM jobs currently and I want to analyze the keywords in each job postings. I found lots of tools online but I want to build my own as portfolio item. Here is it how it should work: 1. Paste a paragraph in a large text input box. 2. Press analyze button 3. Populates a table of two columns Keyword , x (number of times the word appeared in the para) Will greatly appreciate any guidance. In the last 3 months I have learned designing webpages by buying themes and modifying them. Now I am starting to dip my fingers in coding.