Is it permissible for a person with limited knowledge of Islam to invite non-Muslims, explain the basic principles to them, and guide them to sources of knowledge?

There is no objection to conveying what you know of the religion of Allah if you are certain of its authenticity, such as the pillars of Islam and faith to non-Muslims. In fact, it may be obligatory, based on Allah's saying: (And let there be [arising] from you a nation inviting to [all that is] good) and the Prophet's (peace be upon him) saying: "Convey from me, even if it is a single verse." Indeed, some Companions conveyed with little knowledge, such as Al-Tufail ibn Amr, through whom eighty households from the tribe of Daws embraced Islam, among them Abu Hurairah. Some disbelievers may embrace Islam due to the slightest reason and a brief word.