Suitable courses for a content writer with interest in product design and UX design

What is your basic qualification? You have not mentioned it in your question. In the absence of that information giving an appropriate suggestion is a little difficult.
But following are some of the online courses that are useful for content writers.
1. Content writing course by Henry Harvin, a writing academy. Their website is https://www.henryharvin.com/. Their phone number is 9891953953.
2. Udemy is also offering an online course for content writing. Their website is https://www.udemy.com/. They are offering different courses. You can go through their website and select a suitable course for you. Udemy is a leading platform for online courses.
3. Coursera: Their website is https://in.coursera.org/. There are many specially designed courses online for content writers. All courses are online and there are some courses which are free of cost.
4. IIM Skills: Their website is https://iimskills.com/. They have specially designed courses for content writers. Live online lectures for 4 weeks.
5. ECT: Their website is https://ect.co.in/. Their Phone number is +91-7827916060 and their email address is ask@ect.co.in. The institute is having the recognition from Government of India. After course completion, they are offering internships also for some students.

Before query career related questions you should mention your qualification so that we could give good suggestions. Nowadays, there is no dearth of content writer jobs in your interest area. Some of the following can prove useful for your career:-
1. Writing Tools & Hacks: Copywriting/ Blogging/ Content Writing - Udemy
2. Free Online Creative Writing Courses Bundle - Skillshare
3. Creative Writing Certification Course by Wesleyan - Coursera
4. Content Marketing Masterclass

In absence of your basic qualification which you have acquired prior to switching over to the present assignment, the suggestions might not be that much relevant but since you have indicated that you are working as a contest writer currently and hence some courses enriching your knowledge in the following platforms could enhance your job prospects. You might go through anyone of such courses for your career advancement-
1) Udemy- It is one of the largest educational platforms offering over 20400 courses attracting huge learners to opt for the courses for which they are inclined to undertake for their growth in their service life. The following are the advantages of joining of their courses-
1) The session might be quite affordable.
2) If the learners are interested for the free courses, they can opt for 600 such courses covering the topics from Wordpress to Health Fitness.
3) Thirty Days Refund Programme- In case, the learner is not satisfied, they can get the refund of the amount earlier invested or they can choose the other courses of their liking in lieu of the former one.
4) Wide range of the courses for selection- The learners have the opportunities of going through the different ranges which could suit them most appropriately for their growth. Selection would definitely take sometime but with the wise choice, they would be benefited.The courses are divided into several categories for the better choices of the learners of their specific programmes.
5) At the end of the session- The learners would be provided certificates relating to their chosen fields indicating their successful completion of the course.
2) Coursera - The biggest strength of this course is that it has influenced the larger mass of the learners especially the employees ones giving them opportunities to initiate any courses while continuing their jobs. In that way, they find pleasure in managing both their current studies and the jobs doing currently. Thus there are many having completed courses like Computational Photography and understanding Einstein who invented the theory of relativity.
3) IIM Skills - The courses are designed in such a way that it could benefit the learners with their sound concepts in the courses for which they have passions and have joined this platform to be benefited from.
The best part of the course is as follows-
1) Flexible Structure of Class - The courses have been formulated in such a fashion that even the regular employees of any organisation could get benefits of the courses with their joining in online platforms on Saturday and Sundays. They will enjoy the doubt removal sessions even.
2) Even if a learner misses a class, he can avail of the records from the learning management system portal.