Your question sounds to me like you'd like to cultivate social presence (Rourke, Anderson, Garrison, & Archer 2001) on your course.
Getting students to complete their profiles in Moodle is a good start but in order to get them to build familiarity with and trust in each other so that they feel comfortable with and motivated to take the time to share their thoughts and ideas with each other, there's a lot more work to be done.
Personally, I'd suggest integrating student-student interaction with course activities. There's a range of strategies for doing this, e.g. setting open-ended forum discussions and short collaborative projects/assignments.
I think it's important for teaching and support staff to cultivate an atmosphere that's conducive and welcoming to students sharing their thoughts and ideas, and also with the minimum of risk and inconvenience. Since many (most?) students are unfamiliar with how you expect them to conduct themselves and participate (i.e. using educational forums is very different to using social media and informal forums), it can be very helpful to them to model how you'd like students to ask and answer questions, share thoughts and ideas, discuss, etc.. I start with quite intensive involvement, welcoming posts, sometimes responding, often inviting other students to respond, linking to information which supports students' particular arguments, etc., and then gradually participating less and less while the students get more comfortable and confident with their forum participation. I also let students know that this is what I'll do ahead of time, i.e. model -> scaffold -> fade away, which is an underlying feature of cognitive apprenticeship (Collins, Brown, & Newman, 1987), so that they understand that they will have to take over the responsibilities that I'm modelling for them.
Ideally, collaborative activities should be low-stakes but a requirement, e.g. allocate a significant percentage of the final course grade to students' participation (10%+ However, higher percentages can be justified if the course curriculum has teamwork and collaboration skills as part of the intended learning outcomes). You'll also need to decide ahead of time how you're going to grade students' participation so that it has the maximum beneficial effect on learning, collaboration, and motivation. There are some more formal, evidence-informed ways of doing this (e.g. Loughry, Ohland, & Woehr, 2014).
In the spirit of sharing,
Loughry, M. L., Ohland, M. W. and Woehr, D. J. (2014) ‘Assessing Teamwork Skills for Assurance of Learning Using CATME Team Tools’, Journal of Marketing Education
, vol. 36, no. 1, pp. 5–19 [Online]. DOI: 10.1177/0273475313499023
Rourke, L., Anderson, T. Garrison, D. R., & Archer, W. (2001). Assessing social presence in asynchronous, text-based computer conferencing. Journal of Distance Education, 14(3), 51-70.