If you use a word processing program such as MS Word, you must save the mechanism in a text format. Species names can be complex. 2AB3O4 is 2 molecules each with 1A, 3B's and 4 O's. After compiling the mechanism, choose M and load the simulation file, filename.sim. From the menu, choose C to enter concentrations.
Delta time requires some explanation.
Therefore, unless the program crashes, it is best to use a relatively large value. The integrations will define how many points are in the simulated plot. For example, if delta time is 1 and integrations is 1 and the runtime is 100 sec, there will be 100 points. If the integrations is set to 5, there will be 20 observed points on the graph and so on. You can restore these values by choosing R and typing in the name of the .sav set when asked.