Here's my personal tip-
Write the entire essay first. Don’t listen to the critical side of your brain just now. Once you’ve finished your first draft, you can always come back and edit.

When it comes to the “Analyze an Issue” task, they see if a student-

Forms a clear and thoughtful opinion on the issue
Comes up with cogent arguments and examples to support the opinion
Is able to sustain a well-focused, well-organized analysis, connecting ideas coherently
Conveys ideas using effective vocabulary and sentence variety
For the “Analyze an Argument” task, they see if a student-

Forms a clear understanding of the argument
Develops ideas cogently, organizes them logically, and connects them well
Comes up with coherent arguments and examples to support the opinion
Conveys ideas using effective vocabulary and sentence variety

GRE Analyze an Issue task-
The best way to teach is to praise positive actions and ignore negative ones.
Write a response in which you discuss the extent to which you agree or disagree with the statement and explain your reasoning for the position you take. In developing and supporting your position, you should consider ways in which the statement might or might not hold true and explain how these considerations shape your position. GRE Analyze an Argument task-
“To reverse a decline in listener numbers, our owners have decided that WWAC must change from its current rock-music format. The decline has occurred despite population growth in our listening area, but that growth has resulted mainly from people moving here after their retirement. We must make listeners of these new residents. We could switch to a music format tailored to their tastes, but a continuing decline in local sales of recorded music suggests limited interest in music. Instead we should change to a news and talk format, a form of radio that is increasingly popular in our area.”
Write a response in which you discuss what specific evidence is needed to evaluate the argument and explain how the evidence would weaken or strengthen the argument.

Here's some more-
Artless
Meaning - without cunning or deceit
Blinkered
Meaning - To have a limited perspective
Maudlin
Meaning - Overly emotional rambling.
Invective
Meaning - Abusive language
Remonstrate
Meaning - To make objections while pleading

Here are a few tips that will help you with GRE Analytical Writing-

Keep a standard essay structure in mind – Introduction, Problem Statement, Solution, Benefits of the solution, Drawbacks of the solution, Conclusion. Dedicate each para to one heading. Write the entire essay first. Once you’ve finished your first draft, you can always come back and edit. Practice, practice, practice!

Yesss, if you're taking the GRE at home exam-

Create an account on the ETS website. Go to the “My GRE” homepage, select “Register”, and then “Find Test Centers”. Now, select the option for “Test at Home” and make the standard payment of $205. Within a day, ProctorU will send you instructions to create an account along with a link. Use these to log in and select your test date and time.
Once you have scheduled your test, a countdown timer will appear on your dashboard.

Download this guide on how to score a band 8 in IELTS

But if you have spoken to the university you want to apply to
And they are okay with GRE scores
You can take the GRE

Both are very different in terms of what they are looking for, in an answer
ETS has this huge pool of essay topics you can practice from
Hope this helps...

Here are a few suggestions-

Magoosh app is a great place to start You can also try reading Word Power by Norman Lewis

These 2 should be enough for the exam, actually!

Make sure you have an 8’’ x 10’’ whiteboard or a paper with a transparent sheet protector, and an erasable marker
After the GRE test is over, you will be asked to erase all your notes in front of the proctor

Better to give it from home, now

If you want to apply for the GRE exam then you should start preparing at least 3 months before your test date. If your score is less than what you have expected then you can apply again. You can give the GRE exam once every 21 days, and a total of 5 attempts are allowed in a 12 months period. GRE is conducted to analyze a student's aptitude and skills. GRE is both paper-based and computer-based. But most prefer computer-based. It has 4 sections with multiple questions to answer, some written, some verbal so, its better to prepare as early as possible. If you take your test now, your GRE scores are reportable for five years following your test date. For more information, you can check out this link - https://ischoolconnect.com/blog/everything-you-need-to-know-about-gre/