Well, if both the boxes are unopened, you might consider starting a new f2p account and leveling 2 f2p characters to at least level 20 first, before activating the codes on your account. Then, activate the original LOTRO Shadows of Angmar. After that, activate the Moria code on your account. That should give you at least 30 (possibly 60) days of free VIP play time. (The downside of waiting until you level to 20 is that you won't be able to trade silver or list auctions before you activate your game codes.)
The reason to wait until you're 20+ to activate the codes is because the under 20 content is free anyway and you will maximize your VIP playing time with access to the premium quest zones for level 20 and up. Also, once you hit 20 and activate your codes for VIP, you will get a free quest to earn riding skill (rather than having to spend store points).
During your VIP time, be sure to create as many characters and classes as you might ever want to play in the future (up to 7 total per server). All characters created or played during your VIP time will qualify nice perks and unlocks (more bags, gold cap, swift travel, trait slots, etc.).
When your VIP time runs out, you will lose access to most level 20-50 quest zones (except for the 20-30 Lonelands zone). After that, you'll have to buy quest zone access with Turbine Points or pay for continued VIP access (the equivalent of a subscription). So you'll probably want to save Turbine Points for quest packs rather than spending them on other items. The catch is, you can't buy quest packs during your VIP time, so you'll have to save points and wait until your VIP time expires before buying any quest packs.