How do I convert names from English to Lojban?

The rules are here: The Shape Of Words To Come: Lojban Morphology

The summary of the rules are:
* End in a consonant
* Start in a pause or consonant
* Do not include “la”, “lai”, or “doi”, since they are particles introducing names
* Come close to Lojban phonology
* Allow stress not to be on the penult, but indicate it by capitalisation.

Because of the American basis of the Lojban community, you will see djan /dʒan/ more often than djon /dʒon/ for John.

-s is the default final consonant, though some have used other defaults, including -j or -x —because they are less common.

English being schwa-rich, you will see lots of <y> in English names. So Melissa [mɛˈlɪsə] > melisy + s > .melisys. Washington [wɑʃɪŋtən] would be
.UAcintyn.

Are there any short expletives that sound the same in different languages?

Nick Enfield [Page on sydney.edu.au]  (who I did linguistics with, and boy does he look different twenty years on) just got an Ig Noble [Improbable Research] for claiming the universality of Huh? (The Syllable Everyone Recognizes, Is ‘Huh?’ a universal word?)

Of course the realisation of Huh? does differ by language; in the Mediterranean, for example, it is E? But the general idea is a mid vowel (as close to a schwa as your language allows), with a questioning tone.

I’ll note anecdotally that the Greek for Ouch! is ox! or ax!—but that because of cartoons, Greek kids now spontaneously say ouch! (I heard my young cousins do it twenty years ago.) Even though /tʃ/ is not even a phoneme of standard Greek. So short expletives, discomfitingly, can be borrowed between languages, just as everything else can.