Thursdays are known as Guruwar or Brihaspatiwar in Hindi. And since Thursdays are devoted to Lord Vishnu, you may chant the following Mantras. Thus, you can pray to be by offering your devotional salutations.

Vishnu Mantras
ॐ || Om Namo Bhagavate Vasudevaya || ॐ
Meaning:
OM I bow before you O Vasudeva
Vishnu Gayatri Mantra
Om Narayanaye Vidmahe, Vasudevaya Dheemahi
Tanno Vishnu Prachodayat
Meaning:
OM. As I meditate on you, O Narayana, O Vasudeva, bless me with the higher intellect, O Lord Vishnu, ignite my mind by removing ignorance.
Thursday Navagraha sloka
Rigveda the oldest among Vedas describes Lord Brihaspati as a sage born from the first cosmic light, the one who drives away darkness, and is pure and sattva. Astrologically, Brihaspati is the Lord (Swami) of planet Jupiter and is part of the Navagraha in the Hindu zodiac system, considered auspicious and benevolent. Hindus worship Lord Brihaspati and Lord Vishnu every Thursday as per the teachings of sacred scriptures. Observing Guruvar Vrat, fast is considered auspicious to have the divine blessing of Lord Brihaspati.
Dhevānām cha Risheenām cha
Gurum kānchana Sannibham |
Budhdhir bhootam Thrilokesham
tham Namāmi Brihaspathim ||
Meaning :
oh God! you are guru of the Devas and Rushi’s, Who shines like that of gold. The intellectual one Lord Guru to the three worlds(Loka’s) I bow down to you lord Brihaspati.