Whichever language you want to learn make a plan to learn a specific chunk of language everyday. If you follow the plan consistantly, in a short period of time you would have developed enough language competence to use th language confidently.
A sample plan for one of the languages is given here. But this is applicable to any language you want to learn.
For the speaking lessons go to How to Learn to Speak in Tamil
For learning to read Tamil follow this plan. Reading helps you in improving language competence and hence your speech will improve if you are able to read a little bit in Tamil.
Every day learn to read and write at least two letters. During later days combine the letters and try to form words. Try to find the letters and words in a magazine or a newspaper. Try to look for words that you can read from other sources such as advertisements and noticeboards and share with the group in WhatsApp. Do not hesitate to ask questions, offer feedback and suggest corrections in the group.
How to Write the Letters Using GBoard
Download this app from Google Play Store and install it.
After installing the app watch this video and learn how to use it. When you post your answer in the WhatsApp group if you write the letters and words you will get writing practice too.
Now go to the lessons.
Learn Tamil Lesson 1 – two consonants
For each lesson try to find other texts from online that you can read.