But, you will be honoring and glorifying God throughout. And, of course, you would be a woman of love because love means sacrifice. In addition, you would be building habits that will come in very handy when you are married and raising children, God willing. But, you would be living a HUGE example to your kids that some things are more important (e.g., their education) than others (e.g., fancy house or cars). You would be providing the best form of teaching: example.
…If you give as much as you can, He will give you far more in return. Pay attention to this Sunday's readings...God takes our five loaves and two fish (your 10%) and will provide an abundance in return. "God will provide" is the mantra for those of us who give to God until it hurts.
Finally, you probably know the breakdown for the 10%: 5% to your parish and 5% to charities. Hopefully, Newman can be in there somewhere...we would be grateful! :)
Yes, prioritize your budget. I would suggest writing all of your fixed monthly expenses down first - rent, utilities, loans, car/insurance (if applicable). These are the non-negotiables. You might even have the money you're saving for the future in there if you're really disciplined. Ideally, tithing is in there, but for now, leave it out. If you see that you're paying way too much in rent because you chose to live beyond your means, then that's a lesson for your next place. Just ride out the lease. If your loans are too high, can you refinance? Otherwise, these are all fixed monthly expenses for the foreseeable future.
Then, look at all other monthly expenses - food, transportation, clothes, entertainment, etc. Be as frugal as you can while still being practical. Do your best to eliminate waste when you can - if only our government would do this, right! Every little bit here and there helps. But, the idea is to save any dollars you can on yourself and give to God/ the poor. You will feel it, and God will know that you feel it. Still go out with your friends and be generous as you can with family,et al, but just try to sacrifice your own comforts in order to give to others.
So, if it's only a few dollars every month, that will be enough for God. Remember the woman with the two copper coins? She gave all that she had and was commended by Christ. If you do this, it might not be 10%, but it will be tithing in God's eyes. And, my guess is that if you make a habit of prioritizing for the next several years, you will be able to give a larger % in time. It's not about a number, and God probably won't have a calculator for us at Judgment. It's about an attitude, as Professor Sides, of "giving uncomfortably".