Possessive and plural suffixes for proper nouns ending in -s [on hold]

Possessive and plural suffixes for proper nouns ending in -s [on hold]

With a name that ends in -s, such as Travis or Lewis, where and when
should you use -es, -'s, -s or just leave it alone to both pluralise, and
to infer belonging to?
E.g., if the ball belongs to Travis, which suffix would be used in
The ball is Travis[es/'s/s/].
And, referring to a group of people all named Travis, which is correct:
Here come the Travis[es/'s/s/].