(...) However I don't know how to find this kind of cable. I only know that it needs to be a low capacitance cable. (...)
Well, there are quite a lot of suitable cables for the purpose. However, for specific suggestions it wouldn't harm, if you'd let us know, where you're located, which turntable, which cartridge and which phono stage (or respectively which pre-amp/integrated amp/receiver/whatever with integrated phono stage) we'd be talking about - and also which length you'd need and which maximum outer diameter (for example in case the cable would need to fit through an existing strain relief).
That being said, most typically one would choose a decent coax cable type with reasonably low capacitance. Like for example this one, in case you'd need a pretty thin one:
https://www.van-damme.com/vandamme_product/van-damme-miniature-75-ohm-coax Or this one, if you'd like a pretty thin twin cable (W2947):
https://mogamicable.com/category/bulk/video/yc_separate/#gsc.tab=0 Or like this one, if you'd like a very similar replacement for a pretty thin twin "Diodenkabel", as often originally found on Dual and Thorens turntables:
https://www.sommercable.com/en-gb/P...-1-x-0-08-mm2-PVC-5.9-x-2.6-mm-black/320-0061. Or that Diodenkabel version by Kabeltronik with lower capacitance (compared to the Sommer Cable version):
https://www.kabeltronik.de/de/audio-video/diode-and-stereolines/art/diode-line-1/ Just to give you a few ideas.
Well, and for the RCA plugs I'd usually suggest Amphenol ACPR or Neutrik/Rean NYS373 - unless you'd need some for narrow to very narrow jack spacing, in which case you could consider Neutrik/Rean NYS525AG or -BG or even Switchcraft 3502AAU or -ABAU.
Greetings from Munich!
Manfred / lini