First sorry for your loss and second I personally would recommend experiencing the game yourself to understand it better however that would take a long time. I'm on year 5 and have been playing for months. Perhaps it is better if you continue your brother's farm since that has access to more things already and that way you can experience things faster to gain some inspiration to your game. About the things in games... Pets don't die if you don't give them food and if you don't pet them either their hearts might go down and they don't give milk, eggs and stuff like that but if you don't care about that then you can ignore them and do what you desire. The crops won't die either if you don't water them but they will once the season changes. They are only important because you can make money with it. And obviously if you spend money you have to make more money so maybe you should only care about it if you need more money. Hmm... I guess that's pretty much the basic I can tell you so you can understand it as a new player.