You can pray a simple scripture based prayer like the following (see Romans 10:13) -

Dear Lord, I acknowledge that I am a sinner (see 1 John 1:8)

Please forgive me of my sins (see 1 John 1:9)

I confess You as Lord and give you control of my life (see Romans 10:9-10; Luke 9:23)

Please help me to obey Your Word and follow Your ways (see John 14:23; Hebrews 5:9)

Give me the strength to confess You publicly as my Savior (see Matthew 10:32-33)

Thank you for dying on the cross for my sins and giving me eternal life (see Romans 5:8 and 6:23)

In the name of Jesus Christ, Amen (see John 14:13-14; Matthew 21:22)

What to do next?

Make your commitment public.

Follow the Lord in believer's baptism.

Join a church and get involved in discipleship.