Hello and welcome.
Upon completing an offer, your money for that offer is safe for up to 180 days. If you don't request a cashout by day 180, then you will lose the money for that offer on day 181. When you get within a month, you will see warnings in red next to the offers which will be expiring soon on your account page, with a countdown of the days to go before expiring.
So, if you can't make the requirements after 30 days, don't worry, you still have 150 more to go in order to reach $25.00! Just don't forget to cashout when you do!
Good luck.