Firebase database structure review and need help to retrieve it

Here I have structured my example firebase database json. I need to know whether i am doing it correctly or not. And i like to know which db is good for ionic 2+


[
	{
		"months": {
			"month_1":"january",
			"month_2":"Februrary",
			"month_3":"March",
			"month_4":"April"
		},
		"acutal": {
			"acutal_amount_1":"2000",
			"acutal_amount_2":"4000",
			"acutal_amount_3":"4000"
		}
		"spent": {
			"spent_amount_1":"1000",
			"spent_amount_2":"2000",
			"spent_amount_3":"3000"
		}
		"categories": {
			"category_1": {
				"categoryname":"Food",
				"amounts": {
					"acutal_amount_2":true,
					"spent_amount_3":true
				},
				"months": {
					"month_1":true,
					"month_3":true,
					"month_4":true
				}
			}
		}
	}
]