Thanks for answering. I suppose you are right. But where do I start from? John? The psalms? Or just open my NT book and simply start? I guess that's the answer.
I have a very nice edition of the NT, that has, parallel to the original an explanation to modern greek . Which is very convenient and distracting

It makes you want to skip the dictionary, you know? But I will try not to look at it. I don't just want to understand, I want to get into grammar and syntax.
Η Καινή Διαθήκη μετά συντόμου ερμηνείας is the book, it used to be my grandmother's who was very religious. Thanks to her I have several books, and I have added to that small library a few myself. For example I have an old prayer book, and recently I got a new one, with texts from the bible, the psalms, from the fathers of the church, etc. That's a good place to start too, with all its variety.