I have no involvement in the development or maintenance of these online resources, so cannot respond to any enquiries about them.
Sanskrit is a challenge , especially if like myself, you have no grounding in the study of another language. The rewards, however, are immense. Enjoy the study! With you in spirit! :-)
In the relevant Acharya web site pages you will find twelve basic introductory Sanskrit lessons designed and maintained by the Multilingual Computing for Literacy and Education, Systems Development Laboratory, Indian Institute of Technology Madras.
The Acharya Web Site modules are designed so that you can learn the basics of the Sanskrit language through self study. I hope that this introduction will stimulate your appetite for Sanskrit scholarship!
learnsanskrit.org aims to facilitate the task of learning and teaching Sanskrit. It presents aspects of both traditional Sanskrit grammar and classical western philology. It attempts thereby to make the task of learning Sanskrit less complicated.
In their words:
The heart of the site is the grammar guide, which has been under slow but steady development for a few years. Featuring thousands of exercises, more than one hundred lessons, and dozens of images and audio clips, the guide presents Sanskrit grammar in a fresh way without sacrificing clarity, depth, or its enthusiastic spirit!
One issue I have with the Grammar Guide is that it leaves the principles of sandhi (combination of sounds) to the very last. This could be confusing to the student. I recommend that you look at sandhi earlier in your study of Sanskrit.