Seek Jesus
Before anything else, now that you have recognized the fact that God has super-naturally snatched away His people, do not delay in seeking Jesus and making Him the Lord of your heart.
If had been trusting in yourself and some you had done, it's time to start placing your trust completely in Jesus.
Then he said to Jesus, “Lord remember me when You come into Your kingdom.” Jesus said to him, “Assuredly, I say to you, today you will be with Me in Paradise.”
But Paul called with a loud voice, saying, “Do yourself no harm, for we are all here. Then he called for a light, ran in, and fell down trembling before Paul and Silas. And he brought them out and said, “Sirs, what must I do to be saved?” So they said, “Believe on the Lord Jesus Christ, and you will be saved, you and your household.”
What really happened to all of those who disappeared? No, it wasn't aliens!
1Th 4:17 Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord.
If there appear to be non-human beings around claiming to be aliens or anything else, we know what they are: demonic spirits who fell with satan. The Bible warns about satan and his ministers being able to falsely appear to us like angels of light.
2Co 11:13 For such are false apostles, deceitful workers, transforming themselves into apostles of Christ.
2Co 11:14 And no wonder! For Satan himself transforms himself into an angel of light.
2Co 11:15 Therefore it is no great thing if his ministers also transform themselves into ministers of righteousness, whose end will be according to their works.
Mat 24:24 For false christs and false prophets will rise and show great signs and wonders to deceive, if possible, even the elect.