Yes - as long as they're under level 5. Just get me a copy of your character sheet, so I can try to figure out how to balance the encounter accordingly.
Here's a link to the appropriate PDF on the wizards.com site. In short, you're going to make a new Level 1 character, using absolutely no randomization methods behind it. You can choose either the Standard Array (15/14/13/12/10/8) or Point Buy (8/8/8/8/8/8, with 27 points to invest in improving those stats, with the 14th and 15th investment costing 2 points each, before racial bonuses apply). Your character's starting Gold is tied to their Background, and you are given Starting Equipment instead of rolling for Starting Gold beyond what your Background gives you. When building the character, you are allowed the Player's Handbook and One (1) other 5e sourcebook. So for instance, you can create a Half-Elf Mastermind Rogue using Xanathar's as your +1, or you can create a Kenku Assassin Rogue using Xolo's as your +1. But you can't create a Kenku Mastermind Rogue, because Kenku require Volo's, and Masterminds require Xanathar's. The same goes for the spells that you learn - You can't pick up Booming Blade with your Kenku Rogue, as Booming Blade is from the Sword Coast Adventurer's Guide. Once you have a character written up, let me know and I'll check it over.
I actually have modules for all possible tiers - I don't have any issues with running some later if there's enough collective interest. I just figured I'd start with this, since I don't know how to judge the interest level here.
Yep - We're in "Season 9" now, so after you unlock the magical item, you can claim it. Based on your Tier of play, you have a certain number of magical items that you can have on your character at any time. If you're at your cap, you have to get rid of one in order to earn the next. Potions and other consumables (arrows, scrolls, etc.) aren't counted in this.