What does AIDS look like and how do i know if my girlfriend has them?

AIDS is not "them". HIV, the virus that damages the immune system and can lead to AIDS, often has no symptoms for 10 years or more. You can NOT tell if someone has HIV just by looking at them. The ONLY way to find out if you have HIV is to get an HIV test.

Once someone is infected, they can transmit the virus to others, even if they do not have symptoms.

AIDS is an acronym for Acquired Immune Deficiency Syndrome. It doesn't look like anything. AIDS is brought on by contracting the HIV virus transmitted through sex or internal exposure to contaminated blood.
AIDS eliminates your body's ability to fight off infection so, you don't die from AIDS, you die from diseases which your body cannot fight, like pneumonia...

First of AIDS is referred to as "it" not "them"
Second you cannot see AIDS or for the most part any signs of AIDS you have to get tested to truly know

The only way you can know is to get tested. that is why condom use is so important because you cannot see any signs until years later.

you don't know the only way to be sure is get tested together get your results together after you get negative results stay faithful to each other but until you get tested use condoms always

pretty much it wouldnt show the signs til years later
get tested dats the ONLY way you'll know
or use a condom!!
but its better on testin her