If you are attending seminary long-distance, check first to see what services your library might make available to you. Your question seems to focus on access to articles and perhaps books, but there are other and more foundational resources that you also need.
WorldCat is an online database of the holdings of some 40,000 libraries worldwide. There is an academic version, and a public web version. It is essential for locating books you might need via interlibrary loan, and also quite useful for compiling bibliographies. Subsections like ArticleFirst and Dissertations let you search those categories.
The ATLA Database will focus specifically on theological and religious resources. This is another resources that your seminary library should be able to make available to you.
For pre-1923 materials, Google Books and
www.archive.org are two sources that will yield an abundance of Presbyterian and continental Reformed works. With most, you can download entire works as pdf files. The CRC has a portal site with links to continental Reformed works on Google and elsewhere. I'm thinking about preparing something similar for Presbyterian works.
Some journals are online and free [
Themelios, e.g.]; others are available on a subscription basis. For general seminary education, I would instead rely on your library privileges to request print copies of articles from journals on an as-needed basis. Most of your seminary education would be book based anyway, I think, or required articles may be included in the course syllabus.
Then of course there are all sorts of materials posted all over the web. Monergism.com is one vast warehouse. There are a lot of others. The PCA Historical Center has PCA position papers, several hundred articles and a sermon text index for published Puritan and Reformed sermons.
There's a lot out there and it just takes a bit of looking. Come back here to the PB if you prefer and I'm sure someone can always point you in the right direction.