To list or not to list? The answer to the question is rather simple, yet often ignored. If your overall GPA is 3.0 or higher, list it on your resume. If your major GPA is 3.0 or higher, while your overall GPA is below 3.0, list it as your "Major GPA" on your resume. You can list both if they are above 3.0 and your major GPA is at least three tenths higher than your overall GPA. If your university does not calculate your major GPA, you can do it on your own with a calculator or simple spreadsheet. And always round the number to the nearest tenth. I know the Registrar's Office may provide it to the hundredth or even thousandth, but this is not an exercise in higher math. It is acceptable to round up 2.95 to 3.0. It is not acceptable to round up 2.94 (or 2.91) to 3.0.
And yes, the resume reviewer is fully aware that if your resume lacks your GPA, it likely means that you missed the coveted 3.0. Be prepared with a very good reason why you fell short. If you are an undergrad, you may still have time to make up for your earlier carelessness in not keeping up your grades.
An easy content addition for an entry level resume is to add your significant classes under your Education section. Note that listing classes is optional based on the availability of other content for your resume. So if, for example, you already have an internship (or two), you may want to forego adding classes in favor of providing more bullets on what you delivered within your internships. But if you have the lines available on your one page, you can and should include significant classes from your major.
You should include classes within your major that you will have completed by the time you will begin work. So you can include classes that you plan to take, but have not yet completed. Where this becomes somewhat difficult is in the Fall semester listing classes in the Spring semester which you plan to take, but have not yet taken. Yet they will be completed and provide the employer with the benefit of that academic class completion, so they should be included.
List your classes in order of importance. They should not be listed in chronological or reverse chronological order. Which are most important to the employer? Review yourself from the perspective of the employer and consider which classes the employer would value the highest. These are the ones to list first.
You can use a multi-column format with two or three columns, depending on the class titles. Also note that you do not have to use the formal class title. A descriptive class title is better for both your resume and the employer understanding of the class content.
Also note that once you complete college and are working in your first entry level job, the class listing section of your resume is the first section to be removed to make room for details about your first job. Always list what is most important to employers. While your classes may be important at the entry level, they will lessen in importance once you are in the workforce at your first job.
The Activities section on your resume is optional and can be included if you are otherwise unable to fill the page or if you have significant activities you would like to highlight.
In general, you should focus on extracurricular activities which correlate directly or at least indirectly to your chosen career path. Does including the activity support your value in seeking your career objective? If yes, include it. Otherwise, do not.
Your first area of focus should be professional clubs and organizations tied directly to your career field. If you aren't already a member of the professional club tied to your career, join now. And, ideally work toward gaining a leadership role within the club.
Secondary for inclusion should be other extracurricular activities which show particular work or leadership attributes, even though the club or organization itself may not be directly tied to your career. Were you an officer in a club related to your hobby? Or, better yet, its founder? This kind of experience can fill out an otherwise brief resume.
You should typically not include any clubs or organizations which are religious or political in nature, even if you have held leadership roles, unless your target employer is specifically aligned with these views. For example, involvement in Young Democrats on campus should not be listed unless you are applying for a role with the Democratic National Committee, a staff role with a Democratic congressperson, etc. Be very careful and selective in noting any activity which might have a negative view by any portion of the general public. You never know who is on the other end of your resume review and how they might react. Is it legal to discriminate against you for your religious or political views? No, but putting them out there for generic review may mean that you are excluded for other reasons from consideration. There are plenty of other reasons that a candidate may or may not be considered. So the best approach is to only include activities which are positives or neutrals, avoiding those which are potential negatives.
This Activities section of your resume is another section that will go away once you are in the workforce and have gained professional experience.