={"Title1"; A2:A} would set a custom title and then return from the second row in the specified column, but how can I continue this one for the next column? ={"Title1"; A2:A, "Title2"; B2:B} only returns the second column and skips the first one.
>Solution :
You may try:
={{"Title1"; A2:A}, {"Title2"; B2:B}}
OR
=hstack(vstack("Title1",A2:A), vstack("Title2",B2:B))