In the current pandemic, davening in Shul on Shabbat begins from just before the Shema and its blessings. When I say the earlier parts at home, I have worn my tallit – when I come to Shul and put my tallit on again, do I need to make a new bracha?
This is actually a multi-layered question which we will tackle by dividing it into two main parts. Firstly, we must think about whether one needs to make a new bracha when putting on a tallit for the second time.
As a general rule, one does not make a new bracha when putting on a tallit for a second time if one had this in mind when taking it off. This is the opinion of the Rema (OC 8:14), the leading Ashkenaz authority, although he qualifies that this is only true when one is still wearing tzitzit even while the tallit is off (since they are covered by the same bracha). Nevertheless, later commentaries say that this qualification is not necessary if you intentionally take it off – only if it falls off by itself would one be exempt from a new bracha when wearing tzitzit.
However, an additional qualification that all seem to agree to which is that we are talking about someone who intends to put their tallit back on soon after (“מיד”) – the question is how long exactly is that? Some say that this means a gap of a few hours which can be particularly relevant on Yom Kippur when there is a gap between Musaf and Mincha during which many remove their tallit. In our case, I think that a walk to shul would be considered a short enough time not to require a new bracha.
Nevertheless, there a few other details which make a new bracha questionable. Primarily, if one will be putting on a different tallit in Shul then many authorities would require a new bracha even though your original intention was to do so. Additionally, the fact that you will be changing locations also suggests that a new bracha should not be made. In light of all of the above I would suggest not making a bracha, following the principle that we do not make brachot in doubtful cases.
Finally, there is a second layer to this question, namely whether or not one is required to wear a tallit at all when davening the earlier parts (morning brachot and pesukei dezimrah) at home. In truth, our main requirement is to wear a tallit for the Shema and Amida and therefore I would suggest not wearing one at all at home, thereby avoiding the question altogether and simply putting on a tallit with a bracha when you come to Shul.