Since your capital is small,i suggest you increase your capital to 10k minimum and then you can trade swing trading and buy few more shares via mtf or intraday and earn profit
There are various strategies for screening of stocks for swing trading. I suggest you search google or videos on YouTube as well as do your own research and see which one works for you best. Always remember there is no right or wrong strategy. One strategy may work for me but not...
If you goal is for long term,its good. Because of the defence stocks will rise in the future and every year defence budget is also increasing. So its completely safe to invest in lump sum.