Goodness, ptumbi do you really want an answer?
You know enough about the language to know about the gender assignment of nouns, which is a great start. My chatterbox mother managed to live and converse in Germany for decades without ever grasping that point. It's really useful, to start as you mean to go one and learn the gender alongside the word, because 'just knowing' is the only reliable way to find out. That, or DudenOnline, anyway. The fact that you are referring to a woman does not change the gender, though cases (nominative, genitive, accusative, dative) will change the article (or ending for the ein/eine ).
German grammar can seem complicated to native English speakers, because we are not used to the inflections, but also have very little experience of really reliable rules to follow in our language. For any rule in English grammar, it isn't difficult to think of lots of counter examples. German grammar rules tend to be a lot more reliable, with only a handful of exceptions to learn, making it well worth while learning the rules.
A german dictionary, well, nowadays maybe a link to an online dictionary or an app, will be really useful to get the gender clear from the start. If you really want to do well, before to go to sleep at night, think of the words you have learned and check you know the gender. Then make up a story with each word...zzzz.
My experience was that the people who wanted to improve their own English, were very forgiving and flattering and easy to get to know. The people who appreciated my efforts to get to grips with German might have been less obviously charming, but somehow over time, became much better friends.
You get to know most people differently, when you are 'speaking their language,, or at least trying to. For me, it was noticeably more interesting, to get to know people while speaking German. Come to think of it, that may well have been the same for those who were so keen to speak English
All the best. I'd love to hear about anything that puzzles you, it would be great to be in touch with the up to date challenges.