My first instrument was piano, which I would agree is a good grounding for moving to other instruments if you can get past that that first hard couple of years. And if, like me, you had to do music theory alongside it, as well as learn to read music, this stood me in good stead in years to come and moving to other instruments.
I don't know if people will remember a formidable lady called Atarah Ben-Tovim who used to go around the UK schools back in the 60s/70s? She had this theory that ALL children have music in them, and if they didn't get on with the first instrument they tried, this did not not mean that they were not musical, but that they just had not yet found the right one to capture their attention - and there would be a right one somewhere!
One thing I have also found on my musical journey is that each instrument I have taken up has beneficial spin-offs from the previous ones, e.g. I learned more about chords from playing guitar than piano, but this later helped me on when taking up melodeon, and then back again into my piano playing, especially when playing for dancing.
We were lucky in having an inspiring music teacher at school to whom we owe a lot, running choirs, orchestras, producing operas and arranging whole music weekends combined with other local schools.