Sound Proof That Condo
There are actually some very viable sound-proofing options, and if the people who built your condo were smarter, they would have used them from the get-go. But it appears they didn't, so it's all up to you. But first, you should probably contact the condo association, and find out about the rules and regulations related to doing renovations. This is a drawback, and may set you back a bit of time, but on the plus side, you may find out that soundproofing something they already see as a priority, and at least part of your final bill will be covered by the condo association.
Once you've gotten permission, go out and buy either some mass-loaded vinyl, QuietRock or acoustic foam. These are the soundproofing materials of choice for most homeowners.
Mass-loaded vinyl is just that, vinyl siding that is extra dense, making it a superior sound proofer. QuietRock is a gypsum product that incorporates a layer of elastic polymer that actually turns sound vibrations into heat that is easily dispersed into the gypsum. Acoustic foam usually textured to resemble an egg carton, and is the most visible, yet least permanent method of soundproofing. All of these can be installed against any wall, including ceilings. Be extra cautious if you are installing soundproofing on a ceiling, as you don't want to ruin any lighting fixtures, or make recessed lighting so recessed it's ineffective. In fact, be careful installing this everywhere. Never cover electrical sockets, always follow the manufacturers instructions, and when in doubt, contact a professional.
As for soundproofing below you, rubber mats are designed for this purpose which are ideally installed under your flooring, but in a pinch can be laid on top of it, too.
What options you choose really depends on how permanent you want it to be. If the condo association won't let you do a renovation, put some foam on the walls and lay down a rubber mat. If long term sound proofing is your goal, install the gypsum or mass-loaded vinyl everywhere, then add another layer of drywall and paint. A well-done soundproofing job will add a lot of value to your home.