「たり」in ~たりする is a particle used as an adverb. It takes one action or state as an example, implying that there are other similar things.
Example:
A. 今日は一日テレビを見て過ごしました。
Today I've spent the whole day watching TV.
(Watching TV was all she did.)
B. 今日は一日テレビを見たりして過ごしました。
Today I've spent the whole day watching TV and such. ... watching TV and the like, ... watching TV., etc.
(Maybe she played computer games? read manga? etc., besides watching TV)
The sentences you mentioned may be translated as follows:
1. 「着物着たり。。。」
Are you going somewhere fancy, wearing kimono and such?
Are you going somewhere fancy, being dressed up, like wearing kimono?
2.「大きい声で話したり。。。」
Please don't talk loudly, etc.
Please don't talk loudly (and do other disturbing things).
Please refrain from making noise, like talking so loudly.
.