I am trying to prepare to make my very first proton pack but im not sure where to start at? any suggestion?
Are you planning on building it all from scratch or are you trying to buy things in kit form?
In either case you really should try to familiarize yourself with the part names and read over a few existing build threads before you dive in.
Just to add to what Vince said you should also check out the feedback thread and the blacklisted sellers before diving into any purchases.
The Proton Pack Section Index is a good reference tool to have on hand, as it collects a good selection of the replica builds, and reference material the site has to offer.
In addition to deciding on whether you want to scratch-build your Pack, or buy a shell, you may also wish to consider whether you want to replicate a Proton Pack from the first movie or the second, as they both have some considerable visual differences.