Does seeing things (nouns/objects) alter the case to which they belong? I'm a tad confused....but here I still plod on....
I really recommend that you get the Hurra Po Polsku 1 textbook and exercise book.
You can buy them on amazon too but usually they are more expensive.
You could also get a few lessons from Kamila.
She says the first lesson is free. Go to her webpage, click on contact her etc. send her an e mail and you can arrange the first lesson which is free.
polishforums.com/general-language-17/want-impress-colleagues-monday-tell-weekend-polish-61741
The Hurra Series books won't teach you all you need to know but both contain exercises( with answers at the back) which would help you a lot. I don't think that it is possible to learn Polish grammar from the internet alone, without a book you are making the challenge of learning Polish cases/grammar extremely difficult if not impossible for yourself.
I will have to give up on you if you don't get yourself some book to help with your cases. :-( ...............(I am not claiming to know much but I would try to help if I could but you need to help yourself too, buy some books, this would be a giant step forward, getting lessons would be second only to living in Poland)
Best of luck.