mataimandolin

so i ve been playing the mando for about a month and i think im pretty good but im not great and i could use a lot of improvement.
i got one pick when i bought the mandolin and its thin/heavy, but i found another pick at home and its thin. I cracked the thin pick, but i like it better than the thick one.
also the pick occasionally flies out my hand or i find it slipping? is that because of the think im using or is it just i need better pick grip?

THANKS!! this really ...