First time using CDJs

I would plain tell them, that 90% of the world has accepted that CDJs are a thing of the past and you want to bring your controller as you can simply do more. The best clubs in the world (Ministry of Sound, Octagon, Palm Peach, Mocco beach club,…) all allow you to use your own gear to free your creativity. Tell them you need only 30min on your controller to show them and they understand.

If they are not going for that, be professional and tell them you do it, but if they want to hire you, it will cost more as your creative freedom is lessened by playing with their old gear.

As for playing on CDJs. Ask them if their CDJs are Serato ready (the 2000 CDJs are always, but the mixer has to be certified) and up to it. If they say yes, bring a USB hub and cables unless they tell you their tech will connect you. Make sure you have a full Serato license that is valid for use with CDJs (check on serato.com, log-in and your purchases).

If all that is valid, your Serato will work with the CDJs and mixer, then you can simply connect and play like on the SB. Even the knobs look similar, the downside will be, that there are no dedicated effects knobs, so you prolly will need to use the mixers effects (which suck on most DJMs compared to iZotope in Serato) and the channel filters. On 2000s looping is very limited and most likely you only have 3 hotcues available (if they work, it sometimes is hit and miss) everything else is the same as on the SB and also looks nearly identical. You can ignore the built in screens.
Get a high-res picture and the manual of the CDJs and DJM on pioneerdj.com and you can easily check the layout, so you find everything when there.

If the CDJs are not Serato ready then no problem. Download Rekordbox (for free, not the license version Rekordbox DJ). Open it up and transfer the prepared playlist(s) for your set onto a USB drive. It is very intuitive. Make a second USB drive as backup. Go there and put the USB drive in any of the CDJs and push the USB button near the USB slot. Push the LNK (or Link) button on the second CDJ. The displays will help you find a tune and show you the waveforms. Nexus players even have sync buttons and display the waveforms in color on the display along with the BPM etc. so you are fine to go. Of course you can do less than with Serato (hence why good clubs are ditching CDJs as they are overpriced relics) but the layout and style is very similar the SB. So generally speaking you should be fine if you stick to the basics (aka beatmatching, filter effects on the mixer and short loops).

I know the first part of this post sounds like “you can easily say that, you played 20 years and have a name to demand stuff I am new”. Honestly I have some guys I mentor and they were in similar situations. I gave them the same advise and it worked 2 out of 3 times. One of the clubs ditching the old CDJs actually and now demanding DJs to bring their own gear.
Be confident in yourself and your abilities and you will do fine. Be professional about it, do not sound desperate but have answers for them.
I myself I tell clubs simply if they want me to play on outdated gear my fee goes up 50% per hour to compensate for lost creative freedom.

I would mention to them that you don’t necessarily need to re-wire the whole DJ booth as most Pioneer mixers have a spare channel you can plug into, even if all four channels are being used, you can still plug in to one of the four channels and flick the switch from CD/line to phono…

If they are still sticking to there guns, just organize you’re playlist in rekordbox and export to USB and you’re good to go.

Having used CDJ’s in the past the learning curve is about the same as controllers, you’ll be just fine on them.

When i upgraded from my old non rekordbox CDJ’s the 800MK2’s. to the 850’s, i had no problem getting the hang of them and rekordbox.