A - Thanks for the question. Guilt can be a good thing or a bad thing, so sorting it out is necessary. Guilt is good when it is proper - we have done something wrong (or not done something we should) and then we feel guilty. This should lead to repentance. But, sometimes our consciences can be faulty. It can make us feel guilty when we ought not. This is self-condemnation that is not spiritually healthy and leads to scrupulosity - which is an overactive conscience.
With this being said, it isn't uncommon for someone to feel guilty about seeing someone who has so little on the streets while we have so much. Yes, we have a lot. We ought not compare our belongings to those who have more, when we live in the wealthiest country in the world for all of history. So, a twinge of guilt is common and in some ways expected. This isn't necessarily a bad thing. Our response, and our duty, is to always help those who are in need.
Catholic Social Teaching has what is commonly referred to as the "preferential option for the poor". When you feel that twinge of guilt, it is because you feel a solidarity with your fellow human being. Vatican II put it this way:
The joys and the hopes, the griefs and the anxieties of the men of this age, especially those who are poor or in any way afflicted, these are the joys and hopes, the griefs and anxieties of the followers of Christ. Indeed, nothing genuinely human fails to raise an echo in their hearts. - GS, 1Remember that Christ had a special love for the poor and even chose to be born into poverty. As followers of Christ, we are called to imitate his love for others.
So, does this mean that you have to give money to every homeless person you meet? No. That isn't necessarily your job, nor is it necessarily good stewardship of the resources you have been entrusted with by God. Many homeless are addicts or mentally ill. They don't need to have money that might feed their addiction. Rather, it is a good idea to hand them food or give the money to a local charity that can assist them in ways they need. A shelter, soup kitchen, skills training center, etc. is a better option to give your money to.
Yes, all Christians are obligated to help and assist the poor. But not all of us are called to do as Mother Teresa did when she would work hands-on by getting the poor off the streets. Some are called to volunteer time and talent. Some are called to give money to charities. Some are called to give their entire life. What is your call? That is for you and God to talk about - for you to discern.
I hope this helps.