Dhammabodhi wrote: Since I have been doing Anapanasati practice on my own, without any hands-on guidance, will it be an obstruction or cause difficulties in the retreat?
Not at all, as most of your meditation there will be on your own. There are people available to ask questions, but the instructions are done by video recordings.
Any other practical advice, inspiration, wishes and metta are humbly welcomed.
1. If you can, for about a week before, get up at 5:30 a.m. in the morning.
You have to get up even earlier than that at the retreat. When I've talked to other retreat participants after the retreat was over I learned that a number of people slept in, missing large portions of the retreat. Others, who were not used to being up that early, who actually did get up, told me they didn't get much out of that time since they weren't used to functioning at that time of day. It wasn't a picnic for me either, but since I had a job that required me to get up at 5:30 I was able to function decently enough to get use out of that time for meditation.2. Bring ear plugs with you.
You will hear snoring and all sorts of other noise in the barracks, which may disturb your sleep. Your nervous system will adjust to the silence and you will become even more sensitive to all sorts of noise.3. Give yourself at least a day between coming home and going back to your job
Like I wrote in number 2, your nervous system will adjust to the silence and the reduction in distracting stimulation. When you leave the retreat you may feel overwhelmed by the noise, lights and distractions of a city. It will clear up fast, but it is nice to have a day or two to adjust on your own.