26 and 162lbs questions about diet and training

I have been going to the gym for little while now (I train 3-4 days a week) and would like some advice in terms of diet and time frame. When it comes to a time frame if I train hard enough when could i expect to see by April? I’m not expecting a 6 pack however that’s the long term goal. In terms of diet for breakfast I eat plain oatmeal with a scoop of protein powder with Greek yogurt or two eggs, lunch is chinken (x2) with rice, and dinner is chickpea pasta with ground beef. Would you say it’s a good diet or what do you recommend I change? Any advice is greatly appreciated.