Based on charts i believe bitcoin still have a possibility to grow really high on the next year, i do think the door is still opened for investors to invest in cryptocurrency.
You don't have to enter the Bitcoin market when prices drop, joining now is also a good idea, Bitcoin prices are changing every second of the day. You shouldn't panic when you see the price of Bitcoin decrease because the price increase and decrease is a normal thing.
Yes just hold it for a long term like 2 - 3 years and i think bitcoin is good choices for long term.