French language Q&A Forum

I am not sure why it is not leurs, since bottes is plural

Hello there, need some serious professional advice on understanding french language. It's been 2 months since I started learning french, i knew vew few things like numerals, alphabets, and i can able read and comprehend short sentences. My concern is that currently I'm doing everything and retaining nothing up in my brain. I'm watching YouTube videos and reddit and alot more things but unfortunately it's becoming tough day-by-day. I skipped the "conjugation part" and tried to learn vocabulary but that didn't click to me. I feel everything is there but I'm not getting it. 

As an alternative to "des aiguilles de pin," can one write "d'aiguilles de pins"?  Or is "des aiguilles" appropriate because (as I suppose is the case)
"aiguilles" are considered uncountable here?  And why "de pin" instead of "de pins"?

how do you ask.  Who do they love?  Qu'aiment-ils  is WHAT do they love?  but how would you ask WHO di they love?

"Qu' aiment-ils?"  is this  What do they love?    How do you say "Who do they love?" ?

In the sentence "Apres, j'ai invite mes voisins a un aperitif pour faire leur connaissance", I would have thought "leur connaissance" should be plural (leurs connaissances) because she invited "mes voisins".

I chose “voir” and came up with an error.  I’m also doing Duolingo and that says voir is the correct word when visiting someone, hasn’t even mentioned the word “rendre”. Confused here….

Peux-je remplacer  "veuillons, veuille, veuillez" avec "Voulons, veux, voulez"à l'impératif?

J'ai fait plusieurs erreurs avec les pontuation. Je avoir besoin de practiquer.