There is no "Max Motives" cheat code in the original The Sims 1 (PC or Console). The cheat testingcheatsenabled true (which allows shift-click-dragging motives) does not exist in Sims 1—it was introduced in The Sims 2.
If you have Livin' Large or later expansions, the SimVac (Knowledge Aspiration Reward) sucks motives from other Sims to fill yours—risky but powerful.
Focus on Cooking 10 and Mechanical 10 (repair own appliances) for long-term autonomy.