Introductions Introductions or quarantine first?

The ideal way is to put 2 cages close to each other so they can see and smell each other but not be actually together which doesn't really make sense cause if they have a airborne illness the other will still catch it if they next to each other and wait 3 weeks and if the new one shows no signs of health issues then have another person hold one you hold the other on neutral ground and using a towel slowly let them interact humping strutting and a little fighting is normal but separate immediately if you see any blood...but your choice I put mine together right away not knowing any better and they seem fine

Quarantine should be done in separate room to prevent airborne diseases.

If you are getting the new pig from a reputable rescue that have done the quarantine, you can skip the quarantine. Some rescues will even help you with introduction.

Read this article for the best way to introduce guinea pigs.
https://guinea-pigs.livejournal.com/3002707.html

Two weeks? Sounds like a petstore. If so, quarantine in separate rooms.

@Jeff williams, please wait until you have more experience with guinea pigs before offering advice. That is completely incorrect advice for introductions.

@Onlyinred, if you introduce the pigs first, there's no point in quarantine, because they'll have both been exposed to the same pathogens. Quarantine is to protect your old pig from any illnesses the new one may have, and your pocketbook from having to have multiple pigs treated instead of just the new one. Quarantine, if you do it, should be for three weeks, not two, because that's the usual incubation period for airborne diseases. It's your choice as to whether to quarantine or not. As @lissie said, if you get the pig from a reputable source, there's usually no harm in skipping it.

Have you read https://guinea-pigs.livejournal.com/3002707.html?

Other than putting then next to each other it's what the humane society says to do SO guess they wrong then

I doubt that the humane society has much experience in introducing guinea pigs. They rescue them and rehome them. The introductions that we recommend here have been used by hundreds of guinea pig owners and rescues, and we feel completely comfortable in referring people to them.

So what part is wrong then putting them on a neutral ground letting them find each other ? They going to hump they going to strut, they may even fight a bit but as long as there's no blood it's normal if you say they should just get along and do nothing then okay....

Its coming from someone in my area. In that case, i should quarsntine and just hope that after 3 weeks that the new pig and my old pig get along. Correct?

If she is coming from a place where she was well looked after, kept in a clean environment, looks and feels health (clear eyes, normal breathing, good weight etc.) and didn't have any contact with other animals in the recent past then you may not strictly need to quarantine. If she is coming from a background where she may not have been as well looked after as she could have been or had contact with other animals who could have passed an illness onto her then yes I would typically advise quarantine.

How old is the new guinea pig going to be? My personally preference is to skip quarantine altogether for very young guinea pigs (as in younger than 3 months old), unless they have an immediately apparent health issue, as they really don't cope well with being alone when they are very young. I am more willing to take the risk of infecting my other guinea pig than risk the babies health with all the added stress of loneliness in a new strange environment.

Is it coming from a private home, and was kept as a pet? Or a reputable rescue? If so, I might not quarantine. If it's coming from a city shelter, I definitely would.

If it's coming from a friend and you know he/she knew how to keep GP, and the GP looks awesome, then introductions in neutral area is fine. If it's someone you dont know, check the piggie out and cage, make sure everything was kept clean and even then it could be iffy. Use your judgement. Do not put cages togeather, I never yet heard that turns out good. Both GP are in their territory and feel the other will cross it. They don't understand the bars prevent this. Also, if the new piggie has anything, bugs and viruses can cross cage fencing.