A monthly subscription to a gym in the provinces costs 1,000 rubles. I do not know of such a level of poverty, at which a 21-year-old guy could not afford it ...
Whether you can or not depends not on the availability / lack of money, but on the motivation of patience ...
Listen, the main thing is that you have already asked this question. But here the mandatory points should be:
1) An honest answer - why am I doing this.
2) A constant reminder of the need to move towards the goal.
3) The right environment (almost 60% of success in business)
4) Consistency and discipline
In this case, sports will start to make sense, you can do it like this as you find convenient.
What's the difference how much money you have? Buy dumbbells on the same Avito and go. Run. Doing outdoors. Now there are special platforms with horizontal bars and more. Forgive these excuses. There is only one answer - if you really want to and set a clear goal to achieve something, then you will succeed.
You can pump up the main muscle groups and learn to do push-ups, pull-ups and more, if you wish. To get started, start doing exercises with dumbbells Well, if you do not have dumbbells, take 1.5-2 liter bottles of water. Slowly raise your arms to the sides to shoulder level, but not higher, lower to the starting position and repeat. Elbows slightly bent, palms facing down. Then, just as slowly, lower your arms.
Poverty has not motivated to work since the age of 14, has it?
An adult sat at home in poverty from 14 to 21 and did not go to try himself in professional sports, so that a spoonful of soup would be enough?
Of course, you can do sports now, but where sports stubborn character then take, even if poverty is not a motivator?
How is sports related to financial health? You can train without money. No fancy clothes or gyms. Watch a film about footballer Pele.