Can you get an std from using public bathrooms, showers or a bed in hotel?

Only by sex!: They're called "sexually transmitted" for good reason. STDs are not simply infections that involve the genitals. The bacteria and viruses that cause them evolved so that they cannot be transmitted by contacts like this -- only by the intimate contact of sex. (If they were so easy to transmit, they would be common without sex and not called STDs!) Don't worry at all about such things.