Want to apply for a fiance visa?

my girlfriend lives in ireland me in usa and she is 17 when she turns 18 i want to propose to her and get her a fiance visa and help her into the usa please id you would explain in great detail the steps and ways no websites the websites always use big words and stuff that confuse me and make me unsure please just tell me all i know is i need to meet her 1 time within 2 years of the fiance visa unless meeting her would be something that would hurt me in some ways i really love her alot and it is hurting me alot and making my chest hurt cause i have heart problems cause i think we wont be together and i have been through alot of heart break too much for one man to take in the period of time that it has gotten me then i meet her the perfect girl and laws say we cant be together please please help