Herpes can only be transmitted when a sore is active which is pretty easy to see.
Kissing is pretty safe.
I don't know what sandwiching is, you describe it as "getting ready to kiss". I pressume at your age that meens thinking of something that kills an erection? I'm pretty sure that won't transmit an STD.
As you asked about AIDS i'll take a moment to inform you a little. It has a reputation as a gay disease, but it isn't. It can be transmitted by fluid exchange between two persons but does not transmit in saliva (where it is not present). Despite it's reputations lesbians are less vulnerable to it than heterosexual partners.
AIDS earned it's reputation in the 70s when the gay male scene was going through a cultural backlash of promiscuity - but the majority of infections these days are amongst heterosexual couples who dismiss it as something only gays need to worry about (and who do worry about it thus transmission rates are down).
AIDS is not a very virulent disease, once in your body the chances of it taking hold are still quite slight, it can die out once in a new host and it can take a long time to grow sufficient strength to be detectable. For this reason an AIDS test is pretty pointless before 6 months have passed (in order to give the virus time to either establish itself in your body or die out).
It is this difficulty of detection in the early stages which allows the disease to spread so readily amongst sexually promiscious people.
If you believe you have been exposed to the HIV virus you can get retroviral drugs which can help bolster your immune system against it taking hold. However the drugs have some nasty side effects and are only any good if taken very soon after initial exposure.
If the virus does take hold you can live a very long time before the virus developes into AIDS. It is an auto-immune disease which attacks your body's defences against infection, consequently many victims of the disease actually die of other illnesses such as colds which the body is unable to fight against (medicines bolster your body's defences rather than replace them) which can result in death from pneumonia.