Good luck to your journey in the army, the best coin for you to buy is the BTC, ETH, BNB or SOLANA, $1000 is already big capital for investment and if you are planning for a long term then that would be great, one year is also good but would be better if more than one year until we see a big pump for BTC.

The price of the bitcoin now is already high and about to reach its new ATH but it doesn't matter as long as you are planning for a long term investment.