Firstly, muslims and Gaalo are different. The prophet said this world is like a prison for us and like Jannah for non-muslims.
And secondly Allah (swt) does not ignore the dua' of a sincere practising muslim.
However sometimes not in the way we expect.
The answer comes in three ways:
1) The du'a takes places exactly how you asked for it.
2) Allah gives you something better than what you asked for. For example you asked for your ill relative to become better. Du'a is the only thing that can change QADR (fate.) So perhaps Allah will prevent the death of your brother or sister.
3) Allah says in the Quran what we think is good for us is actually bad for us, and what we think is bad for us is good for us. Only Allah is able to see what will happen if such a du'a is answered and he is actually preventing something harmful that might have befallen you.
4) The du'a is granted but spared until the last day where it will turn into good deeds, that could save us from the hellfire.
Sis you just need to be patient, and persist. We should remember Prophet Ayub's story, may Allah be pleased with him. Allah took everything away from him as a test and when his wife turned impatient because of shaytaan, she asked Prophet Ayub to turn to Allah to remove his suffering,
He answered, ''Tell me how long did I enjoy good health and riches?"
She replied: "80 years."
Then he asked: "How long am I suffering like this?"
She said: "7 years."
Ayub told his wife he was ashamed to ask Allah to remove his hardship. because he had not suffered the amount of years he had been blessed. He lost his wealth, his health and his family. Subhanallah - This story brings tears to my eyes.
Allah says in the Quran: "Then We heard his prayer and removed that adversity from which he suffered, and We gave him his household and the like thereof along with them, a mercy from Our store and remembrance for the worshippers." (Surah 21: Verse 84)
Please my sister in Islam, please please study Islam or these doubts will lead to you to having such weak iman that eventually a muslim would leave Islam all together. I myself am not perfect and have many short comings, insha'Allah I will make du'a for you.
There are golden times for making du'a.
Waking up in the middle of the night and praying Tahajud - the nightly prayers. You can pray as many Raka as you want. Another is when it rains because Allah's rahma (mercy) is bestowed upon us. Also on Yowmul Juma - Like an hour or half an hour before Maghrib.
You must have full conviction of Allah and that he will answer your supplication.
Also ask your parents to make dua for you (The parents dua' is readily accepted.)
If you can't do that, then ask someone you know is very practising and religious.