If offering avocado and fruits, do we need to steam them first? if so, for how long? thanks!

Nope, don't have to steam or blend it. It's already soft and creamy by nature so it's pretty much hassle free to prepare it:) I've just started solids for my 6month old boy today with avocados. Just have to mash it with fork, mix a little FM/BM into it and serve. 1 whole avocado is a little much for my boy and I read that it isn't advisable to freeze for the next day's feed (it turns brown) so my sister made avocado shake out of it hahah. Other fruits like apple & pears, you can steam for a couple of minutes and then cut them up in strips if you're practising Baby Lead Weaning (BLW) or if baby is having puree, blend it until your desirex texture :) Philip avent 2in1 steamer is pretty useful and fuss-free for this.