So first off, that doesn’t at all insinuate sex. Don’t get your hopes up for it, that could mean multiple things, and it could easily mean something non-sexual like a massage. That said, you increase sexual stamina by having sex frequently. Doing so will desensitize your nerves to the sexual stimulus allowing you to last longer. There is numbing cream you can use but that takes away pleasure too. That’s about the only way to actually increase stamina. It takes practice and repetition. The first few times, or if it’s been a while, you’re likely to orgasm quickly. That’s okay and it’s normal. Longer erections is a tricky question. You can take a Viagra or cialis if you want to make sure you can (most likely) stay hard, but other then that, a healthy diet and sleep. Erectile dysfunction is a common issue when performance anxiety takes place so try not to worry about it so much. Take it slow and let what happens, happens. As for lasting multiple times, that usually takes practice with sexual intercourse. The hormone prolactin is responsible for you becoming flacid after an orgasm as it raises dramatically in men post orgasm. It typically takes 5-20 minutes to be able to successfully become erect again after an orgasm, during which time you can do foreplay for your partner or use toys. When you get some practice in, you can just keep going through your orgasms but that typically takes practice to get your body used to it. More importantly, you should do homework on and get knowledgeable on how to do foreplay properly. Stop worrying about yourself so much in this regard and figure out how to please her properly and how to give her an orgasm without penetration. Such as with fingers and oral. Learn about the erogenous zones on the body so you can do full body foreplay with her correctly. If you’re a giving partner and get her off before penetration, you won’t have to worry if you orgasm too quickly or don’t know what you’re doing yet, as you were already a good partner. Most men don’t help their partners orgasm. Don’t be most men.