I have 13$ worth of btc.i dont understand what will happen,if i holding this btc for a long time ?
It just depends on how long you hold and what the price is when you sell or trade for goods.
It could be worth $1 or it could be worth $10000
It could be good to hold your bitcoins for a long term, keep in mind there are more risks that you have to take to do this but it will also maybe be more profitable at the end, A long term investment can let you gain a lot of money if the bitcoin grows to a very large currency.
bitcoin prices will always be at the pump to rise. if the future of bitcoin increasingly rare, since halving continue to do, I think prices will continue to rise. so really a good way to hold in the long term.