You can! If you lead someone to Christ, you baptize them.
In most legacy churches, only the trained professional baptizes new believers. There is nothing in the Scriptures to indicate that only a trained professional or a leader can baptize.
John 4:1-2 says this: Jesus knew the Pharisees had heard that he was baptizing and making more disciples than John (though Jesus himself didn’t baptize them—his disciples did).
If Jesus didn't baptize anyone, but passed the job on to his disciples, why would we wait for a leader to baptize new believers?
Paul, in his letter to the Corinthians, says that he baptized only a few of them: Has Christ been divided into factions? Was I, Paul, crucified for you? Were any of you baptized in the name of Paul? Of course not! I thank God that I did not baptize any of you except Crispus and Gaius, for now no one can say they were baptized in my name. (Oh yes, I also baptized the household of Stephanas, but I don’t remember baptizing anyone else.) (1Corinthians 1:13-16)
Who baptized everyone else? In the book of Acts, in every case but one, the passive voice is used (the believers were baptized). We don't know who did the actual baptizing. The only time we are told who baptized someone else is Philip who baptized the Ethiopian eunuch (Acts 8:38), although we can often infer who did.
The important thing is that the person gets baptized.
On occasion, we have baptized someone who has then, in turn, baptized someone else they led to the Lord. We have baptized people in rivers, lakes, hot tubs, even the bath tub.
What do you think?