If none of your family members are muslim, then a muslim Judge(Qazi) may act as your wali, if you can't find one then you may ask any person with the qualification of a judge or witness to act as your wali ... such as an Imam.
If the bride has no Muslim guardian and there is no Islamic magistrate
to act as one, she may authorize a male Muslim who has the
qualifications of an Islamic judge (def: 022.1)--or if there is none,
then a male Muslim who is legally upright (def: 024.4)-to act as her
guardian in marrying her to the groom. Umdat as-Salik, 3.6 Marriage, Section on Guardians, p519
When there are no awliya', the wilayah belongs to the imam and the
hakim( or qazi) because of the words of the Prophet (p.b.u.h), "The
sultan is the wali of one who does not have a wali." Al-Hidayah, Book
of Marriage, p.499 , Alternate translation, see mid-left
A Non-Muslim may not be the guardian of a Muslim.
There is also no wilayah for the kafir (unbeliever) over a Muslim, due
to the words of the Exalted, "And never will God grant to the
unbelievers authority over the believers.."[4:141] It is for this
reason that the testimony of an unbeliever regarding a believer is
inadmissible and they do not inherit from each other. As for the
unbeliever, his wilayah for purposes of marriage is established over
his unbelieving child, due to the words of the Exalted, "The
unbelievers are protectors, one of another ..."
Al-Hidayah, Book of Marriage, p.498 , Alternate translation (see bottom right)
The marriage agreement is not valid without a guardian who is (a) male
(b) legally responsible (mukallaf)
(c) Muslim (d) upright (e) and of sound judgement.
The following may not be a bride's guardian:
(1) a woman (2) a child (3) a non-muslim
Umdat as-Salik, 3.6 Marriage, Section on Guardians, p519
Also see question on islamqa: https://islamqa.info/en/389
and this article on islam-online
In the Hanafi school of thought, a woman may contract marriage without a wali, though its not a recommended practice.
The nikah of a sane and major, free woman stands concluded, when it is
with her consent, even if the wali (guardian with legal authority
granted by the shariah) did not undertake this contract. This is so
according to Abu Hanifah and Abu Yusuf (God bless them) recorded as
the Zahir al-Riwayah.
The basis for permissibility (according to the Zahir al-Riwayah) is
that she has undertaken an act that pertains to something that is
purely her personal right, and she possesses the legal capacity to do
so being sane and in possession of discretion. It is for the same
reason that she can undertake transactions in wealth and possesses the
right to choose a husband.
Al-Hidayah, Book of Marriage, Section on Guardians, Page 491 , Alternate translation, see right under heading of Guardianship
Also see this.
Whereas a non-muslim may not act as a wali for a muslim you may invite your family to attend the Nikah ceremony, and you definitely should invite them to the wedding feast(Waleemah). There is nothing in Islam which forces you to sever ties with your non-muslim family ... indeed Islam tells us the opposite, to treat them with kindness and love.
Quran 31:14 And We have enjoined upon man [care] for his
parents. His mother carried him, [increasing her] in weakness upon
weakness, and his weaning is in two years. Be grateful to Me and to
your parents; to Me is the [final] destination.
Quran 31:15 But if they endeavor to make you associate with Me
that of which you have no knowledge, do not obey them but accompany
them in [this] world with appropriate kindness and follow the way of
those who turn back to Me [in repentance]. Then to Me will be your
return, and I will inform you about what you used to do.
Quran 4:1 O mankind! Be dutiful to your Lord, Who created you
from a single person, and from him He created his wife, and from them
both He created many men and women and fear Allah through Whom you
demand your mutual (rights), and (do not cut the relations of) the
wombs (kinship). Surely, Allah is Ever an All-Watcher over you.
