If they are just the normal earrings in the normal spot it be ok. It depends on how healed up you are. I had to take my earrings out for soccer games after only one or two months, and I didn't have a problem with them healing up in just the one hour. Since it takes six months for your ears to heal up completely, you're going to want to use only safe metals for that time or until they are healed. Safe metals include gold and sterling silver. It's best not to use the cheaper metal on open wounds like this. Be sure and sanitize new earrings with rubbing alcohol before putting them in. If this is your first time with piercings, you're going to want to look in the mirror, and to just try with studs first. Doing it for the first time could be a piece of cake or it could be clumsy like I was. It took me a while before I got the hang of getting the earring to go in straight. It might be painful trying to maneuver them through at first, but they will heal up if you don't get the new earrings in right away.
This is not recommended. You need to keep your earrings in for about 4-6 weeks while cleaning them everyday. If you do not, your piercing may get infected or close up.