Hello and welcome to LLB forum. When you've got the time, take a read through all the Sticky Notes. Lots in there, you will find yourself reading them more than once.
I always drew about 0.5 unit extra in the syringe, to account for bubbles. Turn the syringe needle side up, draw down to make a bigger bubble at top, then tap so the little bubbles join the big one up top. Then slowly twist the syringe, not push, to get out the air, then twist some more to get down to the dose you want. It takes a little practice, but also depends on what type of syringes you have, some are fussier than others or more prone to bubbles. Make sure you slide the syringe up and down a few times before withdrawing insulin, to spread the lubricant and make it easier to more the syringe.