Salam alaykum jazak Allah khair for the question.
The Prophet (peace be upon him) said, “Convey from me even an Ayah of the Quran; relate traditions from Banu Israel, and there is no restriction on that; but he who deliberately forges a lie against me let him have his abode in Hell.” [Sahih Bukhari]
in another similar hadith:
The Prophet (peace be upon him) said: "Convey from me even if one ayah (verse) for it may be that the one being informed will comprehend better that the one listening (at present)." (Al-Bukhari)
From this two ahadith we can see that the Prophet of Allah has told us to pass on anything we know even if it is one ayat. It is wrong to say that we have to be learned before we can propagate Islam. Rather it is necessary for us to learn about Islam then convey it.
It is also very important to be able to give accurate information as related in the ahadith, giving inaccurate information about Islam or telling lies are grave sins. As for relating traditions from the Bani Israil this is only what that doesn't contradict Islam.
It must be made clear that giving dawah takes patience and perseverance and must be in the best manner as Allah (swt) says in the Quran:
"Invite (people) to the way of your Lord with wisdom and good counsel. And argue with them in the best of manners. Surely, your Lord knows best the one who deviates from His way, and He knows best the ones who are on the right path." [Surah Nahl 125]
This is clearly telling us to be in the best manner, as for being anything other, this may deter people from understanding Islam properly which may lead to them having a unintended explanation.
This is only a brief summary I'm sure the brothers have much more to say on this matter insha-Allah.