The conjugation pattern feels like it should follow that of irregular verbs volo, nolo, and malo — even more so because yolo seems to convey a sense of desire or longing. A Latin version of yolo should also probably begin with an i, as words starting with y are hard to come by.
Without further ado:
Conjugation of iolo, iolle, iolui
infinitive
tense
form
translation
present
iolle
to only live once
perfect
ioluisse
to have only lived once
imperative
number
form
translation
s.
ioli
Live only once!
pl.
iolite
Live only once, y’all!
present indicative
person
form
translation
1 s.
iolo
I only live once
2 s.
iovis
you only live once
3 s.
iovult
it, she, or he only lives once
1 pl.
iolumus
we only live once
2 pl.
iovultis
y’all only live once
3 pl.
iolunt
they only live once
imperfect indicative
person
form
translation
1 s.
iolebam
I was only living once
2 s.
iolebas
you were only living once
3 s.
iolebat
it, she, or he was only living once
1 pl.
iolebamus
we were only living once
2 pl.
iolebatis
y’all were only living once
3 pl.
iolebant
they were only living once
future indicative
person
form
translation
1 s.
iolam
I will only live once
2 s.
ioles
you will only live once
3 s.
iolet
it, she, or he will only live once
1 pl.
iolemus
we will only live once
2 pl.
ioletis
y’all will only live once
3 pl.
iolent
they will only live once
perfect indicative
person
form
translation
1 s.
iolui
I only lived once
2 s.
ioluisti
you only lived once
3 s.
ioluit
it, she, or he only lived once
1 pl.
ioluimus
we only lived once
2 pl.
ioluistis
y’all only lived once
3 pl.
ioluerunt
they only lived once
pluperfect indicative
person
form
translation
1 s.
iolueram
I had only lived once
2 s.
iolueras
you had only lived once
3 s.
ioluerat
it, she, or he had only lived once
1 pl.
iolueramus
we had only lived once
2 pl.
iolueratis
y’all had only lived once
3 pl.
ioluerant
they had only lived once
future perfect indicative
person
form
translation
1 s.
ioluero
I will have only lived once
2 s.
iolueris
you will have only lived once
3 s.
ioluerit
it, she, or he will have only lived once
1 pl.
ioluerimus
we will have only lived once
2 pl.
iolueritis
y’all will have only lived once
3 pl.
ioluerint
they will have only lived once
present subjunctive
person
form
translation
1 s.
iolim
May I only live once
2 s.
iolis
May you only live once
3 s.
iolit
May it, she, or he only live once
1 pl.
iolimus
May we only live once
2 pl.
iolitis
May y’all only live once
3 pl.
iolint
May they only live once
My ability to translate other subjunctive tenses gets pretty fuzzy, so here they are as a mental exercise: