What's the SSD? Is it better than a WD Blue? I need help with some questions please.

what CPU does your system have? an SSD will help with load times but if your CPU is on the slower side it wont change much

Well an SSD has the advantage over a Mechanical drive such as your 1Tb WD blue Hdd.
First of all the amount of data it can transfer at a higher speed.
And what we call the Access time.

When you are playing a game and you notice a slight lag or glitch in game play it can be because textures for the game are constantly being requested from the drive to render the graphics in the game, and the details of it.
The cause of that is down to the time it takes a mechanical hard drive such as your 1Tb drive to search, locate and read the data.

An SSD is faster by about ten or twenty times or more in speed when it does this.
SSD drives vary in price based on the amount of storage capacity, but also how fast each SSD drive can read and write data. The price only vary s from £20 to £10 pounds on average between SSD drives based on the size or storage capacity you buy them in. Drives with more Storage space cost more.

No you do not have to remove the current 1Tb WD drive you have in the system, you simply add the SSD to your system as another drive.

When most people buy and SSD drive, they tend to put the working operating system used such as windows 8 or windows 10 on the SSD based drive as it leads to faster loading of the system and makes windows faster and more responsive.

And then also install there favorite games they most frequently play for faster loading of the game it`s self.
I don`t know how much you have in mind of spending on an SSD drive.

But one of the most important things is the capacity, and storage size of the SSD drive.

For example if you bought an SSD drive of about 120Gb. by the time you have formatted the drive for use and installed a working os to it like windows 8 or 10.

You are left with very little space to install all of your games to the drive if you have quiet a lot of games.
The minimum size I would recommend you get in storage capacity would be a 240Gb ssd drive over a 120Gb SSD drive, so you at least have the option to install a few games with free space still left on the SSD drive.

Cheaper SSD drives with the same quoted capacity, are cheaper because the read and write speeds of the drive tend to be lower than one with the same capacity but have a higher price.
So it`s important you take note at the read, and write speeds each SSD based drive can do.

A really cheap SSD drive will always have a very poor read and write speed.