I record in a room were my voice echos and I need help so my voice does not echo My mic is a blue snowball and my recording software is audacity.
Your best bet will be to treat the room you're recording in with absorptive materials to reduce the echo... If you're at home, it can be as simple as hanging a lot of heavy clothes up in front of the walls, especially where you have exposed reflective space on parallel surfaces. The more soft, heavy stuff the better, especially around the spot you're in.
There's a lot more that can be done acoustically, and you should search online for recording studio acoustic treatments... You can build your own broadband absorbers and bass traps from fiberglass or "rock wool" panels for a fraction of the cost of premade products.
This next tip involves changing your performance, but you can also reduce the echo by speaking more quietly, closer to the mic.
If you've done all the above and are still getting undesirable reflections, look for "dereverb" plugins. SPL, izotope, Sonnox and Zynaptiq are all good for different cases. Most of them have free trials. But if you're using these, it's because something was recorded in a less-than-ideal space... And if you're the one doing the recording, you owe it to yourself to get it recorded well, rather than trying to patch it with a plugin later.
Removing reverb/echo is not a trivial task. Only in recent years has it even been developed to the point where it is usable in the Real World. Most solutions are still quite expensive. "De-verb" is a function that is too complex for something as simple as Audacity.
This blog post has some good information that may be helpful: "De-Verb for Free: Removing Reverb using Free Plugins"
It is far easier to avoid reverb while recording. Removing it after the fact is time-consuming, expensive and fiddly.
In a pinch I throw a beach blanket over my head, the desk & the mic, to create a mini isolation tent. And I have to move the bird cage into the next room.
The best solution would be a microphone isolation shield. You can buy one like this, or even make one using plywood, insulation, and a fabric cover.
A simple solution is to use a headset mic like the JK MIC-J_069 headset unidirectional microphone for about $30. Or you can go with the professional headset mics for $200-$400.
The less expensive headset mics are electret microphones which are powered differently than phantom powered microphone. You can plug them directly into you computer or laptop. Otherwise you may need a electret 3.5mm to XLR converter like the Movo FXLR-PRO Mini-Jack to XLR converter for about $20.
Good placement of your headset microphone is at the crease of your mouth where upper and lower lips come together. Good audio quality with minimal breath noise.