If there was anything younger me was going to say to current me it would probably be "...wtf?!" and honestly I'd probably say similar (but with a period rather than an interrobang) seeing as something has gone very awry if timestreams have crossed in such a bizarro manner XD
And also because current me is in completely unimagined never mind uncharted territory for younger me.
What have you done to me!!!! :D
Most importantly... are you getting a Kylie Barbie?
LoL! XD I had to look up what one of those was XD
Also even more amusingly the "younger self" I was thinking of was 17-19 as that's when I started being slightly less stupid and had a slightly higher chance of listening to advice from current me (even if operating on that advice made current me stop existing, or maybe current me would merge into the forked hopefully better version, I haven't figured out that one yet XD). Younger me that was younger than that was probably lucky to survive to adulthood.
What age younger self were you envisioning? :D