Many people who are sympathetic with the plights of black people, LGTQIA (lesbian, gay, trans, queer, intersex, and asexual) and other marginalized groups consider themselves an ally, but they are not.
First things first. We must begin with the question "what is an ally?". An ally is someone who does not fit in the contexts of a marginalized group, but fights alongside them even if their struggles doesn't necessarily have any negative impact on their own life. People of color are often lumped in together although their struggles may be very different, some groups are viewed as "better". If you have any privileges you have to understand them. LGBTQIA people in marginalized group hold even less privilege, in that case a CIS-het person of the same group can include them in their fight and become an ally.
You thinking that something is wrong is not being an ally, it's just you thinking that something is wrong. You actually have to do something otherwise you risk being a person who engages in performative allyship. This type of allyship has been making its rounds among big companies in feigned support of the black lives matter movement. This is when big companies make anti-racist statements but at the same time do not hire POC (people of color), or treat them badly in comparison to their Caucasian counterparts. Performative allyship is when you voice your so called allyship - by lying or not telling the whole truth about your actions. "Don't talk about it, be about it." You cannot, for example, claim to be an ally for black lives matter if you are white but do not know any black people. In that case you are against the injustice, but you are not an ally. How come you haven't made space in your life for the people you fight for? Also, if you openly have to declare that you are an ally, chances are that you're not. Actions, not words.
Putting a picture of a rainbow on your social media in support for trans people is not enough, being an ally means daily work. It means that if you are in a position of power you de-centralize yourself and instead amplify the voices of the oppressed - and learn how to take criticism. You cannot possibly be an ally and offensive at the same time. Listen.
An ally doesn't rely on other people to tell them about their struggles as part of a marginalized group - they do actual research. Relying on someone to be your manual and educator is tiring and sometimes traumatic for that person.
If your aren't doing anything and only agreeing that things are bad, I hate to break it to you - you are not an ally.