There’s a lot of intangibles in cloning. If all goes well and your gene cooperates nicely I would say at least 2 weeks as a minimum; one week to clone and one week to express. Baculo expression may take a little longer than bacterial expression as insect cells grow more slowly, so maybe allow up to a month; one week to clone and 2-3 weeks to express. But if your gene doesn’t cooperate, you can be cloning and/or trying to express for a lot longer than that.

i have a question for which i need some help with.

how you would go about changing the catalytic activity or substrate specificity of an enzyme whose gene you have isolated. Why would you want to do this?

Use gateway cloning, it’s relatively fast. Inhibiting regulatory domain of enzyme can help you in changing catalytic activity (i.e. nonsense mutation may give you gain-of-function)