Its obvious that this confusion arose in your mind only after seeing my answer here.So,i am clarifying a bit more .
It's a fact that all Hindu Shastras are to be studied under one's Guru.This is the traditional system which is followed since time immemorial.That's also why we used to have the Gurukulas where the Gurus impart their knowledge and the pupils learn various kinds of Vidyas,Shastras etc under his guidance.
This trend of learning Shastras from books(or from online resources), by self study, is only a recent one.It's not at all recommended.So,you should not follow it saying "since everyone is doing so,i'll also do the same"
But your problem of not being able to find a Guru also seems to be a genuine one.And , if you see the description of a Satguru that is found in Scriptures ,you will know that finding such an ideal Satguru in today's time is a tough tough ask.
Also, let me explain why reading Bhagavat Gita(BG) even without a Guru can't be dangerous.
There are some Scriptures which are full of mantras.If someone studies those Scriptures without initiation and proper guidance and practically apply the methods given therein then the result can be fatal.
And,chanting mantras by picking them up from books is a sin too.See the following warning for example:
Iswara Uvacha :
Pusthake LikhitAnmantrAn Vilokya Prajapanti Ye || BrahmahatyAsamam
Tesham PAtakam Parikirttitam ||
Lord Shiva said :
Those who chant mantras taking them up from books commit sin
equivalent to killing a Brahmin(i.e one of the major sins).
KulArnava Tantram,Chapter 15,Verse 22.
But BG consists of slokas and not mantras.So,reading it on one's own is not dangerous as such.So,you can read it IMO even without a Guru's guidance.
Better buy a book that have the Sanskrit slokas and the translations in your mother tongue.The first BG that i got belonged to my grandmother which had the Sanskrit slokas along with their translations in bengali , my mother tongue.
I don't think you should read any Hindu Shastras in english unless there is no other option left.
Also, a Guru can be many.Anyone (or anything) who(which) teaches you something is your Guru.For example, the grass is also our Guru because it teaches us to be humble.So,you can treat the book itself as your Guru.Or the translator as your Guru.(You can refer to Lord Dattatreya's many Gurus)