Slang:
The peptide is soluble in water so there is no need for DMSO.
Dissolve the 1 gram of peptide in 10 ml of sterile water and adust the pH to 7.4 using either sodium hydroxide or qmmonium hydroxide. I will ask a pharmacist friend which is better.
I will walk you through the process once you get the peptide. You will need a pH meter or at a minimum pH paper, and 20 or so 1.5 ml plastic microfuge tubes. These will be used for storing frozen aliquots of the peptide solution. Many university labs have these tubes, so if you know someone that works in a lab, just ask, these tubes are very cheap. You can also buy them from Sigma-Aldrich chemicals, or a number of online suppliers. Do you access to a lab?