Psalms 65:2 O thou that hearest prayer, unto thee shall all flesh come.
Psalms 86:3 Be merciful unto me, O Lord: for I cry unto thee daily.
Psalms 102:17 He will regard the prayer of the destitute, and not despise their prayer.
Psalms 141:2 Let my prayer be set forth before thee as incense; and the lifting up of my hands as the evening sacrifice.
Proverbs 15:8 The sacrifice of the wicked is an abomination to the LORD: but the prayer of the upright is his delight.
Proverbs 15:29 The LORD is far from the wicked: but he heareth the prayer of the righteous.
Jonah 2:7 When my soul fainted within me I remembered the LORD: and my prayer came in unto thee, into thine holy temple.
Matthew 5:44 But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
Instruction on how to pray:
Matthew 6:5 And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward. 6 But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly. 7 But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking. 8 Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him.
9 After this manner therefore pray ye: Our Father which art in heaven, Hallowed be thy name. 10 Thy kingdom come. Thy will be done in earth, as it is in heaven. 11 Give us this day our daily bread. 12 And forgive us our debts, as we forgive our debtors. 13 And lead us not into temptation, but deliver us from evil: For thine is the kingdom, and the power, and the glory, for ever. Amen. 14 For if ye forgive men their trespasses, your heavenly Father will also forgive you: 15 But if ye forgive not men their trespasses, neither will your Father forgive your trespasses.
Luke 18:1 And he spake a parable unto them to this end, that men ought always to pray, and not to faint;
Luke 21:36 Watch ye therefore, and pray always, that ye may be accounted worthy to escape all these things that shall come to pass, and to stand before the Son of man.
Philippians 4:6 Be careful for nothing; but in every thing by prayer and supplication with thanksgiving let your requests be made known unto God.
Colossians 4:2 Continue in prayer, and watch in the same with thanksgiving;
1 Timothy 2:8 I will therefore that men pray every where, lifting up holy hands, without wrath and doubting.
James 5:16 Confess your faults one to another, and pray one for another, that ye may be healed. The effectual fervent prayer of a righteous man availeth much.
Answer to prayer is according to the will of God.
1 John 5:14 And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us:
We must avoid asking for the wrong things for the wrong reasons.
James 4:3 Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts.
May I suggest that you read:
Does God Hear Prayer?: https://www.thisisyourbible.com/searchresult/163
I hope you find this helpful.