There are some advantages to buying the higher tier packages, namely instant access to bigger stash size (doesn't sound like much but this game can give Tetris a run for its money for inventory management outside of raids...), More starting gear and cash (which you'll lose / replace as you play anyway), higher starting trader rep (saves having to grind a few quests right at the start) and the Gamma secure container - this is probably the biggest advantage but as mentioned above, larger secure containers are available to everyone through the game anyway.
I've only got a standard account and just learnt to be quite brutal with what I keep on my stash and only buy when I need to. The addition of the hideout has definitely added some more longevity / end game purpose as well now which is nice.
Advice for when you're first starting, make the most use of your Scav runs. They're a no loss option that can help you learn the maps and get valuable loot and resources with no drawback if you die; it only has a timer (20 minutes by default) before you can do another Scav run. PMC runs will be hard at the start of the game, don't get disheartened if you die a lot and/or struggle to kill other people - take your time in the raids, move methodically and make the most of any shots you take!