MC is very easy. Probably easier than dwarf hair grass.
DIY co2 is better than nothing but I highly recommend a pressurized co2 system. It is one of the best investments you can make in a planted tank.
Don't try to go cheap you will probably regret it later. Get some good equipment and it will last you a long time. If you go serious in this hobby you want better equipment later and this means your buys now will be a lose.
Personally I like the chihiros rgb units. I have the 60 version on my 80 cm. If you only go for mc and dwarf hair grass (mostly green plants) chihiros a series is also good.
Get a good aqua soil (ADA, Tropica, Dennerle) and if you want a big slope put some lava split under it to go cheaper. With a good aqua soil beginners can grow plants like a pro. They are really helpful.
Do as much research as you can about growing plants. If you use hardscape (wood and stone) I recommend getting a mock tank (wooden box, cardboard box) to practice with it (same dimensions as tank)Take this slowly and never rush it. You will look a long time to your tank and it is not easy to make a good hardscape. Make pictures of the hardscape as it is easier to look at that, than with the eye IRL. I recommend a mock tank with just play sand so you won't crush the soil or hit the glass with a stone. It is also easier to practice because you have no front wall.
Good flow to bring co2 and ferts to plants is important. A good basic rule is 10x turnover filter. So 100L tank means a filter that with 1000/l per hour.
DIY co2 is tricky to get a stable co2 input. Co2 fluctuations can lead to Black beard algae which is hard to remove.
Look for a inspiration tank and try to copy it. It will still look different because you have different hardscape. Your own success will come later.
Good sites for this
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There is so much information for beginners I could go on but just read the internet for good tips. Research, research!!