75g first *real* attempt at planted
I really like budget builds! Everyone can build amazing aquariums with gobs if money, but it takes skill and patience to do something brwath taking on a budget. Love how you have the light propped up on the filter on one side and using the legs to hold it up on the other side. For a budget setup that's looking good, you got some nice pieces of driftwood. Since your on a budget a good way to get some decent plants is to keep an eye out in the WTB/RAOK section, once a week or more I usually see someone offer up a trimming package for $5-$7 and it will contain 5+ species of plants and decent portions of each too. Also make a want to trade post within your states sub forum, I've met a few people that live near me and swap plants with them, you may meet someone nice that would be willing to give you some stuff. If all else fails you can "harvest" some plants from nature, it's a good idea to, know what the plant is, you can always ask here someone is bound to know and give them a quick bleach dip before using them.
Not sure if the star grass will grow very well without co2 but it may! With co2, high light and fertilizer I have to trim my star grass once a week, but I also keep mine about 2 inches tall. If you are still saving up for co2 you could give DIY a try, you can usually get a decent DIY setup going for about $10 or less. Basically for a cheap DIY you just need a chopstick (used as a diffuser), some air tubing, a plastic one-way valve, a 2 liter or bigger bottle with a airtight lid, some sugar, and finally some yeast (if you want to get fancy get a heating pad from your grandmas house). There are different kinds of yeast out there, I have heard that people get a stronger and more consistent flow when using brewing yeast, the kind used for making beer and wine, there is probably a store near you that sells home brewing goods and you can get it from there, or you can order it online, the regular yeast for making bread also works well. Another tip I have read in the past but have not ever really seen much about it since is the use of brown sugar instead of white sugar, this is supposed to help keep the yeast alive longer but don't quote me on that! DIY systems are easy to put together, I am sure there are some excellent write ups on TPT about how to make them and probably a YouTube video, so I am not going to go into detail about that.
What kind of light are you planning to upgrade to? If you want to try it out you can make a really good led light yourself. The price of chip on board (COB) led modules have really come down in price over the past couple of years. Is that a 4 bulb T5 or T5HO? If it's HO you may already have too much light without having and co2 or fertilizers. You want to make sure you don't have too much lighting, because without co2 and fertilizers you will melt all your plants.
You will eventually want to upgrade from that AC110, Hang on back (HOB) filters aren't really good for tanks that tall, although it can handle the volume it will never be able to get the detritus from the other side of the tank or off the bottom. I cannot tell in the photo but you are going to want to have your intake tube as close the the substrate as possible. A good idea would be to keep your eye out for a decent canister filter, sometimes you can get a good deal on a used on, but if I were you I would save up and get a SunSun, they are the same if not better quality than Fluval filters and are not expensive, another benefit of the SunSun filters is they have a very strong flow, so you can use the out flow into the aquarium to create all the circulation you will need to provide a healthily environment for your plants. If you plan to stick with the AC110 you will eventually need to get a power head or circulation pump to keep the water moving.
Where are the fish? Maybe I am just not looking hard enough in the picture.