I think I spent basically the whole day working on Japanese, but it did help me to get an hour break during lunch and stop later in the evening, excluding reading. So it’d be around a couple of hours for SRSing on WK, Bunpro and Kitsun, a couple of hours for reading and then a couple more+ for grammar studies in the middle of the day. I really love learning languages, so I tried and try spending all my free time on them 
I started reading almost immediately, but that was very painful xD I didn’t mind looking up basically every single word but it can be really daunting and discouraging. I’d recommend looking into this amazing thread - Comparison of Book Club Picks and see the comparisons^^
I started with Yotsuba (with the help of the vocab list) and 時をかける少女, which gave me a biiig boost. You can see the books I read and the order here if you’re interested 
https://bookmeter.com/users/977428 But I’d recommend reading whatever interests you, some people like NHK easy, for example, or playing JRPGs, to each their own!