Just burn the CDs to your phone? You can get digital audio off a CD and put it on whatever device you want, no idea why someone would give up their CD collection without at least backing it up to a hard drive first. Even if you don't have any PCs with a disc drive, you can get a USB DVD-ROM drive (or even BD/BDXL if you wanna play blu-rays or save backups to BDXL discs because AI has murdered the price of SSDs/HDDs) pretty cheap.