It's not that complicated.
Forex on retail level is mostly speculation.
The definition of investment ,- something that has value and produce cash flow.
Thus, Fx, stands for speculation.
But, from a practical side,
you could try using TA and economical predictions for that matter, to turn few lots into ,,long term investment", say to protect your local currency Lira (for example), and then buying US dollars, (exchanging Liras to Dollars), but then, you have to be good at that.
Yet, that wouldn't make too much sense, since, buying good companies, in stable countries like US/UK etc, at the right time & for a good price, would produce much better results, over the longer time like 5 or 10 years.
If you're from Russia by any chance, the best returns will come from ,,evacuating'' into Finland, & starting a new life there, or, at least, staying/living there until life in Russia, gets back to normal.