When starting out as a DJ it's a good idea to decide what type you're going to be. There are two basic types: Mobile DJs for special events And DJs that work the club or bar scene You will need a larger cross section of music as a mobile DJ as you will be catering to the tastes of many mixed audiences. The cheapest way to find out whether DJ'ing is for you is to find a friend or local community centre that already has some equipment. This way you can save some money to spend on tunes which you will need in abundance to practice on. If you decide DJ'ing is for you, you will eventually need to get some equipment. You will need two record players (decks) or CD mixers designed for DJ'ing.
Technics 1200/1210 are the industry standard for record decks and Numark CDN 88's for CD mixing are also good. The difference between this equipment and the CD/record players you have at home is the built in pitch control. The pitch control allows you to change the speed of the music which you will later need for mixing. You will also need a mixer to change between tracks without gaps in the music. A mixer can be used in the two main forms of mixing songs either for 'scratching' when a record or on some high end CD mixers the CD is moved back and forth to manipulate the sound.
Or beat matching when one song is layered across another at the same speed to produce a smooth track change. It's likely that if you are just starting out your fist gigs will be in venues that don't have much equipment. If you are going to be a mobile disco DJ you will need sound equipment and lighting. In most cases you will need to take all if not some of your equipment to the venue.
For venues that do not have their own sound system you will need to take some proper mobile disco equipment including speakers and an amplifier. These can be hired but if you are going to make this a full time hobby or profession it's cost effective to buy them instead. If you are lucky enough to find yourself DJ'ing in a night club with its own equipment it's still a good idea to bring your own slip mats (these go on the record platform of the deck) and needles if using vinyl. If you are using someone else's equipment it makes good sense to get there early to figure out how it works. You will also need a decent microphone as you may be expected to make announcements and a good set of headphones. The sealed back variety is preferred by DJs as they cut out all background noise.
Whether you're planning to make a living out of DJ'ing or just as a hobby the main thing is have fun and enjoy what you do.
Showtime Mobile Disco offering advice on how to book a mobile DJ, become a mobile DJ and plan a party.