Is it considered usury if the state buys you the necessities for your project, to be paid in installments with a very low interest, in exchange for taking your educational certificate and not requiring you to seek a government job?

If the state purchases supplies for itself and then sells them to you at a deferred price payable in known installments, there is no harm in that, even if the price is greater than their value. However, if the state pays the price on your behalf to the entity owning the goods and then collects that price from you with an interest-based profit, this is forbidden. The difference lies in the state's ownership of the supplies; if it owns them and sells them to you, it is permissible. But if it merely pays their price on your behalf with an increment, it is a forbidden interest-based loan.