[kingstoned]

If you want to get a visitor visa to attend an incubator like YC, is it better to:

1) wait to be admitted into YC and get B1 visa for 3 months. Do you get some kind of invitation letter from YC that increases your chances of approval?

2) get a normal tourist visa now and specify you will go to the US for a week or two like a normal tourist and later use that to go to incubator training.

[proberts]

There's no need to get a new B-1/B-2 visa to attend YC if one already has such a visa. But when to try to get such visa if one doesn't have it already, whether before or after getting accepted into YC, will depend on a variety of factors specific to that person, such as his or her countries of citizenship and residence, current employment/student status, U.S. immigration history, etc.