Simple IRA--How to make the most of it?

My employer is offering a Simple IRA with 3% match (which will be about about $2k) in 2021. I maxed out my Roth IRA (via Vanguard) in 2020, and plan to do so for as many years as possible before I retire. I have never been offered any retirement options by previous employers, so I am navigating this Simple IRA and wondering how to make the most of it. Do I put the bare minimum in or put in as much in as I can afford this year? Is the compound interest decent with a SIMPLE IRA like with my target index funds? Can I choose to have the Simple IRA through my Vanguard account? Can I choose to put it toward my target index funds (like I do for my Roth IRA)?

I see that at some point I can transfer my Simple IRA to a traditional IRA, what do I need to know while I’m putting money into the Simple IRA when looking at the long term, and possibly switching accounts to make the most of the investment? And, how exactly do Simple IRAs and Traditional IRAs differ?

I’ve never had a simple IRA but I’m guessing it’s similar to a 401(k). You most likely will have a limited choice of index/target date funds. The broker (Fidelity/Schwab/Vanguard) will be picked for you, but the funds inside could be from different brokers.

You definitely want to put the maximum amount the will match (if you can).

The compound interest (growth) is based on the funds (index/target) that you’re invested in.

The process should be very similar to the Roth IRA just very limited funds with probably higher fees.