How can anyone answer such a question? If your kula etc is important to you , you can do research and refine your question.
Otherwise, here is a suggestion. Take Surya devatha (Sun) as God . Call it Suryanarayan if you wish. Surya is a witness to all. Everything that you interact with is only due to sun. Learn to chant and know the meaning of Gayatri Mantra. Your deity is Surya and your mantra is Gayatri Mantra