Questions

Ok so I have a couple questions about blowjob related stuff and this is gonna be really long. Bear with me. Firstly, I'm not very experienced at all. I've given blow jobs a total of three times and only ever with the guy I'm with right now. The last two times he said he's gotten really close to coming but hasn't actually came yet. I always get worn out after going 10+ minutes. What can I do to get him to finish? Then my other question is where should I have him finish. He's asked me where he should when he does but I really don't know. Should I ask him to finish like in a towel or something or should I try to swallow or have him do it on me somewhere?