Blowjobs, SOS!

I recently became sexually active. I had sex twice with my SO. I'm new to trying new things so I'm really keen about giving him a blowjob. The thing is, how do I even start it? Obviously the point is to have it in your mouth but how exactly do I do that? I feel bad because he goes down and me so surely I can give him it in return. Can y'all give me advice please? I'd appreciate it!