Can a straight guy be with a lesbian?
Only if the lesbian agrees. Is she's a lesbian then she is probably not at all interested in men, do don't get your hopes up.
Practice makes perfect. Do you're research. If you're a straight girl, watch heterosexual porn. If you're a straight guy or lesbian, watch lesbian porn. (Straight porn is generally only about the man's pleasure. Most women fake orgasms.) If you're a gay guy, watch guy on guy. You can do this with erotica. Ask your friends. Look things up. Read articles about sex.
From what I have heard, it is common for girls to get turned on by a woman, because some women like watching lesbian porn, but are straight. It's strange. Straight men dont usually like watching gay porn but will watch lesbian porn, and straight women can like lesbian porn and straight porn, it's really strange.
not necesarily.... They could be really good friends, or they could be lesbian. There are other stuff too, like they could be bisexual (a girl or guy who likes both guys and girls) transgender (simply put, a girl who wants to be a guy or vice versa) lesbian (a girl who likes other girls). They could be undecided. Or they could be straight, just really good friends.
No, not all straight women turn to a lesbian lifestyle in their lifetime. However, there is a small percentage of straight women who have had bad luck with men in general and may choose to have a lesbian partner; or in a small percentage some younger women are talked into being bisexual or made to believe they should be in a lesbian relationship.
You kiss a straight girl the same way you kiss a lesbian. If you are asking "How do I get a straight girl to kiss me?", then the answer may be --- be yourself and if she likes you also, then eventually she'll share a kiss with you. Of course if she has a crush on you then she is Bi and not really straight.