Mapping files from NCBI and Qiime2 Question(s)!

Question

[coolsav2010]

I'm a relatively new person when it comes to using bioinformatics software i.e. qiime. My main goal is to use data from NCBI SRA to make an otu table and taxonomic analysis of data from a couple studies using there raw data. The software I am trying to use is Qiime2, specifically the Linux VM of it on Virtual Box. The questions that I've been having are,

1. Is the Accession list from SRA the same thing as a mapping file?

2. How do I run qiime scripts in the Linux terminal?

3. How do I know if my data has been demultiplexed, as the data I have is only raw fastq files? Also, is there anyway to know if there are barcodes part of my raw data?

4. How do I import my data into Qiime from a folder on my VM?

5. Which OTU reference table is the best, given that the data I am using is amplicon 16sRNA data? Specifically, the data I am using is 16s RNA data which represents all the spices present in a sample of a patients Gut Flora. I have 153 files, from two studies, with each file representing a different patient.

Possibly-If anyone is really good at this as is willing to help me by putting out the steps I have to do to achieve my goal, I will be very, very grateful.