What steps did the Tokugawa shoguns take to keep Japan insolated and to create stability in Japan??

Answer 1

They destroyed or fired upon any foreign vessels that entered their waters. Only the Dutch and Chinese were allowed to trade with Japan and they were cooped up in Nagasaki.

As for internal stability they required all lords to make visits to Edo to pay homage to the shogun every other year. Their families remained in Edo as permanent hostages to ensure the loyalties of the lords.

The lords had to make expensive processions and maintain lavish accomadations in Edo thus keeping their funds low so they couldn't finance a rebellion.

Gun manufacturing was also strictly controlled by the Shogunate.