If you want to retire by age 50 years old you need to start putting a good portion of your income into savings and only buy what you need to get by.
Avoid spending on unneeded things.
You should aim to put $500.00 per month or more into your retirement savings account
If you save $500.00 per month in 20 years you will have saved $120,000.00 plus that income will grow overtime if you have it in a savings account and by 25 years you'll have even more money saved.
If you put more into savings such as $1,000.00 per month if possible then you will have $240,000.00 in 20 years just from what you saved. The interest you earn will of course double that amount of money.