Alchemy is a Blockchain developer platform with a variety of different products to streamline the whole dApp lifecycle. From local development to running it in production.
Their <a href="https://www.alchemy.com/supernode">Supernode API</a> offering provides developers reliable access to the Ethereum Blockchain Network. Other solutions revolve around notifications as well as remote monitoring and debugging.
While paid plans are an option they also offer a generous free plan which should be more than enough to get you started.

Alchemy

Participating in the Ethereum Blockchain Network requires a connection to an Ethereum Node. With Infura you can get API access to a Node without running one yourself.
Their generous free plan should be more than enough to get you started with your Smart Contract and dApp projects. Once outgrown, upgrading to the next tier is a matter of a few clicks.
Protip: Infura allows you to connect to their network via WebSockets (<code>wss://</code>) which can help you save bandwidth and API credits with read- and write heavy operations.

Hosted RPC Nodes for Ethereum Virtual Machine (EVM) based Blockchains.

Infura

The "TypeScript Eth Starter" project is an effort to help you get started with dApp development via an opinionated boilerplate.
Once downloaded and installed you can leverage pre-configured tools like TypeScript, Next.js, Hardhat, useDapp and Tailwind CSS to build your full stack dApp in record time.

Template to kickstart dApp development for Ethereum Virtual Machine (EVM) Blockchains.

TypeScript Eth Starter

This blog post written by Nader Dabit teaches you everything you need to know to build and launch your own EVM-based NFT Marketplace.
Working through it you'll use technologies like Next.js, Tailwind CSS, Solidity, Hardhat, Ethers.js and IPFS to create your own ERC-721 Smart Contract, publish the NFT to IPFS and display it via a frontend written in React.
The codebase for the project can be found on <a href="https://github.com/dabit3/polygon-ethereum-nextjs-marketplace/">GitHub</a>. If you're a visual learner you can check out the accompanying <a href="https://www.youtube.com/watch?v=GKJBEEXUha0">YouTube video</a>.

Learn how to build your own NFT Marketplace from scratch.

Building a Full Stack NFT Marketplace

This ~5 hours video course teaches you everything you need to know to build and deploy dApps on Polygon.
Working through it you'll learn about the Polygon Ecosystem, the matic.js library, the Token Bridge, Meta Transactions on Polygon, how to integrate Chainlink Oracles, how to run your own Polygon Node and more.

Polygon

Alchemy

Infura

TypeScript Eth Starter

Building a Full Stack NFT Marketplace

Full Course on Polygon Development - Build Blockchain Apps on Polygon