[I want to update my gig.]

If you have not get any order it will not effect much,

But if you have sell before you should not then it will effect you can not imagine.

And most of all if your profile reach a lot of people you should not change it better option for you.

******Warm wishes from DESIGNLOGOCITY********

[I want to change my whole gig, will that affect my visibility ?]

The best option is Try not to change,

You should make a new gig.

But if you are new have not sell and don't have any order you can change , and most of all if your profile reach more people then you should not change .