You can get the glass cut at any glass store. Just measure the inside of your tank and tell them what you need. Use silicone to glue the glass. I'm sure we can help you do that if you bring the stuff to our meeting. Glass and silicone will cost you about $30. Depending how much bubbles you have in the sump, you might not need as many baffles as I have in that pics.
In this hobby, age doesn't matter but $$ does. If you can't afford expensive equipment, try to keep something that is low maintenance such as softy, macroalgae. Keep up with the maintenance on your tank like clean the glass. Do WC weekly or at least every two week. Keep your equipment clean. When thing dirty, they don't work well. Attack the problem before it get worse. I manually remove hair algae in my tank every week. It's just a small patch but if it's not taken care, it will spread. Don't get too many fish.. Go slow, making sure thing is happy before adding new stuff.. Everything in this hobby cost $$$...